Fix Clock: Difference between revisions
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How to fix an XO laptop suffering from problems with the [http://en.wikipedia.org/wiki/Real-time_clock Real Time Clock] (RTC, or clock). If the laptop has security enabled, this problem may prevent booting, usually with the error "Invalid System Date". |
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= Problem Description = |
= Problem Description = |
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Laptops with this problem show one of these symptoms: |
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# The laptop screen lights up and shows "Invalid System Date" and then powers off, or continues to boot, seeking an activation lease. Activating the laptop will result in the laptop working temporarily, but returning to the same problem on next boot. Affects XO-1, XO-1.5, |
# The laptop screen lights up and shows "Invalid System Date" and then powers off, or continues to boot, seeking an activation lease. Activating the laptop will result in the laptop working temporarily, but returning to the same problem on next boot. Affects XO-1, XO-1.5, XO-1.75 and XO-4. |
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# The power LED turns on, but the screen never turns on (not even the backlight). The microphone LED may flash briefly, but stays off. This symptom can only happen with very old versions of [[Firmware|firmware]] ([[OLPC_Firmware_q2d05|Q2D05]] and [[OLPC_Firmware_q2d06|Q2D06]]). Affects XO-1 only. |
# The power LED turns on, but the screen never turns on (not even the backlight). The microphone LED may flash briefly, but stays off. This symptom can only happen with very old versions of [[Firmware|firmware]] ([[OLPC_Firmware_q2d05|Q2D05]] and [[OLPC_Firmware_q2d06|Q2D06]]). Affects XO-1 only. |
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# The power LED turns on for only about 0.8 of a second, then turns off, and the screen never turns on<!-- mechanism: real time clock oscillator manually stopped by firmware or kernel programmer -->. Affects XO-1 only. |
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# The boot animation never stops<!-- mechanism: time_t is negative due to kernel seeing year 1963, elapsed time calculations fail in powerd, and so powerd never unfreezes the display on boot, see #12621 -->. Affects 12.1.0 and 13.1.0 only. |
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= Diagnosis = |
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These symptoms are caused by bad date information stored in the Real Time Clock (RTC) chip. There are three ways that the date could become bad: |
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* The RTC chip lost all power. The RTC chip has a "coin cell" backup battery (ML1220) that powers the RTC chip when the AC and the main battery are not present. Power may have been lost because: |
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** The battery discharged during storage. This is common. |
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** Some of the early production XO-1 machines were manufactured with a defective holder for the coin cell battery. On those machines, the coin cell battery can become loose or even pop out entirely during normal shipping and handling. |
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** Leakage or corrosion from the battery, causing a loss of contact between the battery and the metal contacts inside the holder. [http://dev.laptop.org/~dsd/20090406/ Some photos here.] |
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** It is also possible that the coin cell battery ceased to work. |
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* The factory did not set the date. This is rare. |
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* The user explicitly set the date to an incorrect value, either by mistake or as an attempt to defeat activation security. This is also rare. |
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These symptoms are caused by bad date information stored in the clock. |
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= Cause = |
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= RTC power dynamic = |
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The following diagram shows the causes of the problem. The colours have meaning: |
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In understanding this problem, it is necessary to understand the power dynamic between the system, the coin cell battery, and the RTC chip. |
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* blue boxes are possible signs, symptoms, or observations, |
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* green boxes are deduced causes, or diagnosis, |
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* red boxes are the resultant problems. |
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[[Image:Ofw-fix-clock-causes.png]] |
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The XO must maintain power to the RTC chip at all times, even when the system is powered off. When power is lost, the time and date will be forgotten, resulting in the problems described on this page. This is especially important to consider for XOs in storage, or XOs that will not be used for an extended period of time. |
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There are several causes: |
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The coin cell battery acts only as a <em>backup</em>: when available, the main power source (AC power or the main system battery) is used to keep the clock ticking. When there is no other power available, the coin cell battery takes over. |
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* The clock lost all power, which is by far the most common cause. The clock has a "coin cell" battery (ML1220) that powers the clock when the AC and the main battery are not present. Power may have been lost because: |
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** The battery discharged during storage. This is common. |
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** Some of the early production XO-1 laptops were made with a defective holder for the clock battery, which can come loose or even pop out during normal handling. |
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** Leakage from the battery, causing corrision, a loss of contact between the battery and the metal contacts inside the holder. [http://dev.laptop.org/~dsd/20090406/ Some photos here.] |
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** The clock battery ceased to work. |
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* The factory did not set the date. This is rare. |
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* The user set the date to an incorrect value, either by mistake or as an attempt to defeat activation security. This is also rare. |
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See [[/Background|background for how this works]]. |
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The coin-cell battery is somewhat rechargable. On the XO-1, it will recharge from the main power source while the laptop is powered on and fully awake (not suspended). The XO-1.5 and XO-1.75 will charge the coin cell battery when the laptop is powered on and fully awake, and also when it is suspended. When recharging an empty battery, it is expected that the battery will reach normal voltage levels after around 30 minutes of charging, but will require potentially 24 hours for a complete recharge. However, the battery is only marginally rechargable - it may stop working completely after 30 deep discharges. |
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= Root Cause = |
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A voltmeter can be used to perform some basic checks on the health of the battery. After 30 minutes of charging from empty, a reading of around 2.7v would be reasonable. After 24 hours of charging, when the battery should be fully charged, a reading of around 3.1v would be expected. However, these checks are unconclusive, 'bad' batteries may produce such readings. A real test would need to measure battery capacity, which is non-trivial. |
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This is a firmware bug. The problem is fixed in the latest firmware, compare the diagram above to the new diagram below, which shows how the latest firmware will respond: |
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When no other power is available, the coin cell battery is only able to power the RTC chip for a limited time before running out of power. Assuming the RTC battery is fully charged, the following table indicates the expected lifetime of the coil cell battery before it is unable to keep the RTC chip powered. |
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[[Image:Ofw-fix-clock-causes-q2f19.png]] |
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{| border="1" class="wikitable" |
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! Laptop model !! Coin-cell battery life |
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|- |
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| XO-1 || 4 months |
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|- |
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| XO-1.5 || 2.5 months |
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|- |
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| XO-1.75 || 12 months <font size=1>(expected, needs testing)</font> |
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|} |
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For laptops without a lease, they will boot normally with the date set to 2013. For laptops with a lease, they will boot seeking a new lease from the school network. |
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When placing XOs in storage or some other situation where they will not be used for a significant period of time, it may be worth considering inserting the main laptop battery and ensuring it has a high amount of charge, so that the RTC chip remains powered for an extended amount of time before the coin-cell backup takes over. According to tests done in Uruguay, the following table provides an indication of how long the main battery can keep the RTC chip powered before running out of charge, in the case where the battery initially had 80% charge: |
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However, the bug strikes before the firmware checks for a new version, so you must repair. |
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{| border="1" class="wikitable" |
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! Laptop model !! Main battery longevity |
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|- |
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| XO-1 || 73 days |
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|- |
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| XO-1.5 || 174 days |
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|- |
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| XO-1.75 || 164 days |
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|} |
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= Repair = |
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Note that the above numbers should be used as indications only; the real numbers will vary based on environmental conditions such as the temperature of the storage area, the exact model of the laptop and the RAM included, firmware version, etc. |
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The repair process is: |
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# [[#Check_the_battery_and_holder|check the battery and holder]], |
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# [[#Set_the_clock|set the clock]], |
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# [[#Upgrade_the_firmware|upgrade the firmware]], |
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# [[#Charge_the_clock_battery|charge the clock battery]], and; |
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# [[#Check_the_clock_is_set_after_removing_power|check the clock is set after removing power]]. |
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Here are English and French diagrams of the process: |
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The overall process is: |
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# Examine the battery and its holder, securing the battery in place if necessary |
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# Reprogram the time and date |
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#* If running a very old version, update [[Open Firmware]] to the [[Firmware#Firmware_Releases|current version]]. |
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# Perform a verification test |
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{| border="1" cellspacing="0" cellpadding="2" class="wikitable" |
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Here are English and French diagrams of the process: |
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! English |
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[[File:Debrick-4.png|thumb|left|English 'date fix' diagram]] [[File:Debrick-4-fr.png|thumb|left|French 'date fix' diagram]] |
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! French |
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<br style="clear:both" /> |
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|- |
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| [[File:Debrick-4.png|thumb|centre|]] |
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| [[File:Debrick-4-fr.png|thumb|centre|]] |
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|} |
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== |
== Check the battery and holder == |
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To access the |
To access the clock battery, remove the main battery, and power cable, and follow the [[Disassembly_top|instruction for removing the back cover]]. |
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=== XO-1 === |
=== XO-1 === |
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Examine the battery and its holder. Is there any sign of acid leakage? Can the battery move in its holder? |
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On newer models of the XO-1, the clock battery and its holder may be covered by a circular strip of rubber to try to fix this. You can remove this cover by peeling it off. |
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Remove the battery from the socket. Check for signs of leakage underneath the battery, in the holder, and on the motherboard and components around the battery holder. |
Remove the battery from the socket, by prying underneath with a plastic tool. (Just removing the battery will fix symptom #3, when the power LED turns on for under a second). Check for signs of leakage underneath the battery, in the holder, and on the motherboard and components around the battery holder. |
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'''If there are signs of battery leakage''': |
'''If there are signs of battery leakage''': |
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# Remove the leaking |
# Remove the leaking clock battery and discard it. |
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# Carefully clean any leakage/corrosion in the battery holder, using e.g. a damp toothbrush. |
# Carefully clean any leakage/corrosion in the battery holder, using e.g. a damp toothbrush. |
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# Neutralize the leakage/corrosion area with some baking soda. |
# Neutralize the leakage/corrosion area with some baking soda. |
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Line 89: | Line 84: | ||
#* If present, you are advised to treat the motherboard as broken or dead-on-arrival. |
#* If present, you are advised to treat the motherboard as broken or dead-on-arrival. |
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# Obtain a replacement cell battery (these parts are very standard) and install in the socket. |
# Obtain a replacement cell battery (these parts are very standard) and install in the socket. |
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#* Any decent electrical/DIY store will stock these, they are known as ML1220 batteries and commonly found in calculators. |
#* Any decent electrical/DIY store will stock these, they are known as ML1220 batteries and commonly found in calculators. |
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#* (Never use CR1220; they are not designed to be recharged, will not run the clock for very long, may leak, and may erupt in fire.) |
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[[image:white_battery.jpg|thumb|If your battery holder is white, then you shouldn't have a problem here.]] |
[[image:white_battery.jpg|thumb|If your battery holder is white, then you shouldn't have a problem here.]] |
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[[image:motherboard.jpg|thumb|The battery holder in the motherboard.]] |
[[image:motherboard.jpg|thumb|The battery holder in the motherboard.]] |
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[[image:XO_bad_rtc.jpg|thumb|Bad |
[[image:XO_bad_rtc.jpg|thumb|Bad clock battery holder (from earlier laptops model) - notice the straight grip]] [[image:XO_good_rtc.jpg|thumb|Good clock battery holder - notice the curved grip]] |
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Line 106: | Line 102: | ||
(these crude diagrams are exaggerated) |
(these crude diagrams are exaggerated) |
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If your XO has a defective holder, you must re-seat the |
If your XO has a defective holder, you must re-seat the clock battery and secure it so it doesn't come out again. This can be done by putting a drop of glue where the battery contacts the holder, away from the metallic contact. |
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* The best glue that Mitch has found for this purpose is clear solvent-based household cement. Technically, it is "nitro cellulose" cement. It is also known as "model airplane glue", marketed under various trade names such as "Duco Cement", "Tarzan's Grip". Loctite "Stik'n Seal", etc (Alleskleber, in Germany, maybe?). The solvent in this kind of cement is toxic and flammable, so keep it away from children! |
* The best glue that Mitch has found for this purpose is clear solvent-based household cement. Technically, it is "nitro cellulose" cement. It is also known as "model airplane glue", marketed under various trade names such as "Duco Cement", "Tarzan's Grip". Loctite "Stik'n Seal", etc (Alleskleber, in Germany, maybe?). The solvent in this kind of cement is toxic and flammable, so keep it away from children! |
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* Stronger adhesives like epoxy or cyanoacrylate (super glue) would probably work too, but it might be difficult to remove the battery later without damaging the holder. |
* Stronger adhesives like epoxy or cyanoacrylate (super glue) would probably work too, but it might be difficult to remove the battery later without damaging the holder. |
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Line 120: | Line 116: | ||
[[image:Xo_1_5_coincell.jpg|thumb|New XO-1.5 battery holder]] |
[[image:Xo_1_5_coincell.jpg|thumb|New XO-1.5 battery holder]] |
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On the XO-1.5, the |
On the XO-1.5, the clock battery is not in a holder. The battery is encased in shrink tubing, and connected to the motherboard with a short cable. (Eliminating the socket was an attempt to reduce the number of socket issues experienced on XO-1.) The battery, in its protective tubing, is stuck down to the motherboard to prevent it from moving around. |
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Even though the same standard ML1220 |
Even though the same standard ML1220 is used, replacing the battery alone is difficult. The shrink tubing will be destroyed as you open it, and it will be difficult, and perhaps even dangerous, to reconnect the wires to a replacement battery. |
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* It may be possible to repair the tubing with some tape, or to discard the tubing and create your own enclosure with some electrical tape. |
* It may be possible to repair the tubing with some tape, or to discard the tubing and create your own enclosure with some electrical tape. |
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* The battery shipped in the laptop is a ''leggy'' battery - it has the wires spot-welded to the battery during fabrication. It is a very bad idea to attempt to solder wires to a new battery (it can explode). It is far better purchase ''leggy'' replacement batteries (e.g. [http://www.pchub.com/uph/laptop/602-25682-4052/Sanyo-ML1220-Battery-Coin-Rechargeable.html here, maybe]). |
* The battery shipped in the laptop is a ''leggy'' battery - it has the wires spot-welded to the battery during fabrication. It is a very bad idea to attempt to solder wires to a new battery (it can explode). It is far better purchase ''leggy'' replacement batteries (e.g. [http://www.pchub.com/uph/laptop/602-25682-4052/Sanyo-ML1220-Battery-Coin-Rechargeable.html here, maybe]). |
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Line 132: | Line 128: | ||
See above, the same battery, packaging, and wiring is used as in the XO-1.5. |
See above, the same battery, packaging, and wiring is used as in the XO-1.5. |
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=== XO-4 === |
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== Reprogram the time/date == |
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See above, the same battery, packaging, and wiring is used as in the XO-1.5. |
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Note that in all cases, the date/time should be set to the [http://en.wikipedia.org/wiki/UTC Coordinated Universal Time] value, rather than the time in your local timezone. |
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== Set the clock == |
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=== If the screen turns on and you can boot into Linux === |
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There are several methods to fix the clock, depending on the symptoms: |
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This is the best situation to be in. It happens if the laptop has activation security disabled, or the laptop without a date is able to retrieve an activation lease. |
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* if the [[#If_the_screen_turns_on_and_you_can_boot_into_Linux|screen turns on and you can boot into Linux]], the easiest situation, which happens if the laptop has activation security disabled, or the laptop without a date is able to retrieve an activation lease, |
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Once Linux has booted, login at a root terminal (e.g. press Ctrl+Alt+F1). |
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* if the [[#If_the_screen_turns_on_but_you_cannot_enter_Linux|screen turns on but you cannot enter Linux]], the next easiest, |
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* if the [[#If_the_screen_does_not_turn_on|screen does not turn on]], the worst situation, the power LED will be on, but a bug will stop the firmware before it turns on the screen, or; |
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* if the [[#If_the_screen_does_not_turn_on_and_nor_does_the_power_LED|screen does not turn on and nor does the power LED]]. |
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The clock must be set to the [http://en.wikipedia.org/wiki/UTC Coordinated Universal Time] value, rather than your local time. |
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Set the system time using the <tt>date</tt> command, e.g. for the current date/time: |
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date --utc --set="{{CURRENTYEAR}}-{{CURRENTMONTH}}-{{CURRENTDAY}} {{CURRENTHOUR}}:{{CURRENTMINUTE}}:{{CURRENTSECOND}}" |
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(The numbers in some of the commands below are the time and date in UTC ({{CURRENTYEAR}}-{{CURRENTMONTH}}-{{CURRENTDAY}} {{CURRENTHOUR}}:{{CURRENTMINUTE}}:{{CURRENTSECOND}}), but in reverse order; second, minute, hour, day of month, month, and year. When you visited this page, our Wiki server used it's own clock to generate this command for you.) |
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Then [[Shutdown|shutdown]] normally and the system time will be stored in the clock. |
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=== If the screen turns on and you can boot into Linux === |
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(Don't force a shutdown by holding down the power button, because then the change won't be stored.) |
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In this situation, you must boot Linux, login at a root terminal (e.g. the [[Terminal_Activity|Terminal activity]], or press Ctrl+Alt+F2 to get to the [[Console]]). |
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=== If the screen turns on but you cannot enter Linux === |
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Set the system time, type: |
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Reprogramming the time and date can also be done using the firmware. |
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sudo date --utc --set="{{CURRENTYEAR}}-{{CURRENTMONTH}}-{{CURRENTDAY}} {{CURRENTHOUR}}:{{CURRENTMINUTE}}:{{CURRENTSECOND}}" |
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Then copy the system time into the clock, type: |
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If there is something visible on the display, you simply need to disable the XO laptop security system and press the escape key once you hear the [[Startup_sound|startup sound]] to access the OpenFirmware prompt. See [[Ok]] for how to do this. |
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sudo hwclock --systohc |
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On XO-1 with releases 12.1.0 and 13.1.0, the above may hang for ten seconds and show a warning<!-- <trac>12622</trac> --> "''wait for clock tick timed out''". The hang and warning may be ignored, the clock will have been set. If you would like to avoid the hang and warning, type: |
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To disable the security system (assuming it is enabled, which is generally only true for large deployments and G1G1 customers), you will need a [[Activation and Developer Keys#Getting a Developer Key if the Machine Won't Boot|"developer key"]] for this machine, on a USB drive or SD card. |
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sudo hwclock --systohc --noadjfile --utc |
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=== If the screen turns on but you cannot enter Linux === |
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At the ''ok'' prompt, type this command to set the clock: |
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ok select /rtc decimal {{CURRENTSECOND}} {{CURRENTMINUTE}} {{CURRENTHOUR}} {{CURRENTDAY}} {{CURRENTMONTH}} {{CURRENTYEAR}} set-time |
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In this situation, you must use firmware to set the clock: |
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You can now turn off the machine by pressing the power button for a few seconds. |
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*[[collection stick|disable the security system]], |
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The numbers are the time and date in UTC ({{CURRENTYEAR}}-{{CURRENTMONTH}}-{{CURRENTDAY}} {{CURRENTHOUR}}:{{CURRENTMINUTE}}:{{CURRENTSECOND}}), but in reverse order; second, minute, hour, day of month, month, and year. |
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*turn on the laptop and get to the [[Ok]] prompt, |
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*set the clock, type: |
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select /rtc decimal {{CURRENTSECOND}} {{CURRENTMINUTE}} {{CURRENTHOUR}} {{CURRENTDAY}} {{CURRENTMONTH}} {{CURRENTYEAR}} set-time |
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You can now turn off the machine by pressing the power button for a few seconds. |
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When you visited this page, our Wiki server used it's own clock to generate this command for you. |
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=== If the screen does not turn on === |
=== If the screen does not turn on === |
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In this situation, you must: |
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Very old versions of OpenFirmware for the XO-1 laptop had a bug which would cause the screen to fail to power up when this RTC clock problem was encountered. If this happens, the recovery procedure involves linking up a special cable to another computer, and then using that other computer to reprogram the time and date. |
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* connect a [[Serial_adapters|serial adapter]] to the XO-1 and another computer, see [[Serial_adapters#XO-1|where to connect it]], |
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(There are numerous opportunities for error, so if you have more than one XO-1 laptop practice serial console communications with working ones before debugging broken ones) |
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* use [[Serial_adapters#Software|a serial terminal program]] on the other computer to access the XO-1 via the adapter, |
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* turn on the XO-1, and you should soon see "Page Fault" on the serial terminal, followed by an "ok" prompt. See [[/Log/Q2D06]] for what it may look like. If you don't see "Page Fault", there are several possibilities: |
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** if you don't see anything on the serial terminal, either |
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*** the serial adapter is not connected correctly, |
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*** the serial terminal is not configured correctly, see [[serial adapter#software|settings]], or |
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*** something else is wrong with the XO-1, perhaps it is quite quite dead and it's not an instance of this known clock problem after all. |
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** if you see a lot of startup messages, and the last one isn't "Page Fault" followed by "ok", then the machine is not suffering from the this known clock problem, but may have a broken display or display cable. |
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* using the serial terminal, type this command to set the clock: |
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select /rtc decimal {{CURRENTSECOND}} {{CURRENTMINUTE}} {{CURRENTHOUR}} {{CURRENTDAY}} {{CURRENTMONTH}} {{CURRENTYEAR}} set-time |
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* restart the laptop, type this command: |
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bye |
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* check that the screen lights up. |
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See [[/Log/Q2D06]] for what is expected on the serial terminal. |
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# Using an [[Serial_adapters|OLPC serial adapter]], connect the laptop to your personal laptop or computer. On the laptop's motherboard, the serial adapter should be connected to [[XO_Motherboard_Repair|J1]]. J1 is a small white connector near the wireless module. |
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# Use a program like [[Serial_adapters#Linux|screen (for Linux)]] or HyperTerminal (for Windows) to access the laptop serially. |
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# The serial port settings should be 115200 baud, 8 data bits, no parity, and 1 stop bit and handshake parameter is disabled; only the baud rate needs to be set on Linux, the remaining settings are the default. |
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# Power on the laptop under test. You should see "Page Fault" on the serial terminal, followed by an "ok" prompt. If you don't see "Page Fault", there are several possibilities: |
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#* If you don't see anything on the serial terminal, either |
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#** The serial terminal is not connected correctly, or |
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#** Something else is wrong with the machine - the machine is quite quite dead and it's not an instance of the symptom 1 RTC problem. |
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#* If you see a lot of startup messages, and the last one isn't "Page Fault" followed by "ok", then the machine is not suffering from the known RTC problem, but may have a dislodged backlight cable. |
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(There are numerous opportunities for error, so if you have more than one XO-1 laptop practice serial communications with working ones before debugging broken ones). |
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Using the "other" laptop that is connected serially to the affected XO, type these commands at the ''ok'' prompt (hitting enter after each one): |
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ok select /rtc |
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ok decimal |
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ok sec min hour day month year set-time |
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=== If the screen does not turn on and nor does the power LED === |
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sec, min, hour, day, etc in the previous command should be numbers correlating to the current date. For the current time: |
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ok {{CURRENTSECOND}} {{CURRENTMINUTE}} {{CURRENTHOUR}} {{CURRENTDAY}} {{CURRENTMONTH}} {{CURRENTYEAR}} set-time |
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You must remove the clock battery briefly to fix this problem. If you did that, and the problem persists, then the cause is not the clock. Have the motherboard serviced. |
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At this point, update the firmware to a version that does not suffer from this blank-screen problem. That way, if the RTC loses power again, your diagnosis/recovery procedure will not need a serial adapter. |
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== Upgrade the firmware == |
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# Insert a USB key containing the [[Firmware#Firmware_Releases|latest firmware version]]. You will need to download the ''.rom'' file and place it on the key. |
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# To update the firmware, type the following command line at the ok prompt, substituting the correct ''.rom'' filename: |
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ok probe-pci probe-usb flash u:\q2d16.rom |
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Upgrade the firmware to make sure this problem does not return. See [[upgrading firmware]] for the latest firmware. |
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== Perform a verification test == |
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If you had the blank-screen problem, the firmware must be upgraded to the latest version. If not, and the clock loses power again, the repair will need a serial adapter again. |
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With the clock reprogrammed, you should verify that the laptop is able to retain the time and date, otherwise this problem may resurface. |
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If you wish to manually upgrade, and you used a serial adapter and saw the "Page Fault" message, you must probe the PCI and USB before manually upgrading, type: |
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# Unplug the charger if it is plugged in. |
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probe-pci probe-usb flash u:\q2f19.rom |
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# Remove the regular XO battery from the underside of the laptop (Note: this refers to the main battery that is charged through AC power, and can be easily accessed by turning the laptop upside down. It does not refer to the coin cell battery, which you should not touch at this point). |
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# Leave the laptop in this state for 3-5 minutes |
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# Connect a power source (the battery, or the charger) and turn on the laptop |
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# Look carefully for an "Invalid System Date" error message appearing immediately |
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Or set the clock, allow time for the clock battery to charge, and use the usual [[upgrading firmware]] method. |
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The lack of an error message indicates that the repair was a success. You may wish to go into Linux and run <tt>date</tt> in the Terminal activity to verify that the clock was programmed correctly, although this should not be necessary. |
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== Charge the clock battery == |
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If there is an error message, then 3 situations are possible: |
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# The RTC coin-cell battery is faulty and must be replaced. |
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Leave the laptop turned on for at least 30 minutes to charge the clock battery to normal levels. |
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* Half an hour is the [[/Background|minimum charge time]] before testing, for which you can use the main battery, |
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* The best charging time is 24 hours before storage, for which you must use a power adapter, |
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* Charging does not happen with the laptop on and suspended; the power LED must be on and not flashing, |
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Easiest method is to remove all USB drives, then hold down all four game keys while turning the power on; the laptop will eventually fail to boot and wait for you to ''Use power button to power off'', with the start time displayed in UTC: |
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Boot failed |
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OLPC C2, 256 MiB memory installed, S/N SHC92805B50 |
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OpenFirmware Q2F19 EC Firmware Ver:1.2.1 {{CURRENTYEAR}}-{{CURRENTMONTH}}-{{CURRENTDAY}} {{CURRENTHOUR}}:{{CURRENTMINUTE}}:{{CURRENTSECOND}} UTC |
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Use power button to power off |
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Or boot to [[Ok]] prompt. |
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Or boot to Linux and disable automatic power management. |
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== Check the clock is set after removing power == |
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Verify that the laptop is able to retain the time and date, otherwise this problem may return. |
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# Unplug the charger, |
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# Remove the main battery from the underside of the laptop, (not the clock battery), |
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# Leave the laptop without power for five minutes, |
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# Connect a power source (the battery, or the charger) and turn on the laptop, |
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# Check the clock using either the [[Ok]] prompt or by running <tt>date</tt> in the Terminal activity. |
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If the clock is still wrong, then 3 situations are possible: |
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# The clock battery is faulty and must be replaced. |
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#* You can verify this by installing a known-working battery, reprogramming the clock, and then repeating this verification test. Test pass would confirm this problem. |
#* You can verify this by installing a known-working battery, reprogramming the clock, and then repeating this verification test. Test pass would confirm this problem. |
||
# There is a problem with the battery holder or the motherboard, so the laptop should be replaced. |
# There is a problem with the battery holder or the motherboard, so the laptop should be replaced. |
||
#* You can verify this by installing a known-working battery, reprogramming the clock, and then repeating this verification test. Test fail would confirm this problem. |
#* You can verify this by installing a known-working battery, reprogramming the clock, and then repeating this verification test. Test fail would confirm this problem. |
||
# If you are dealing with a defective shape battery holder, perhaps the |
# If you are dealing with a defective shape battery holder, perhaps the clock battery is (still) not maintaining electrical contact with the connector inside the battery holder. |
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= Automated repair script = |
= Automated repair script = |
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XO-1 only. |
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Repair center volunteers have created an automated python script that can be used to repair machines in bulk or simply as a method with fewer instructions. The script can be run on a typical Linux machine or on an XO. We call this 2nd computer your "debricker" machine. |
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Repair center volunteers have made an automated script to repair laptops in bulk or as a method with fewer steps. The script can be run on a Linux computer or on an XO laptop. We call this second computer your "debricker". |
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The script you will run on the "debricker" can be found here: |
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To use it you must install ''pyserial''. You must be online when running (any of) the three following commands: |
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[http://dev.laptop.org/~rsmith/d6.py d6.py] |
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For Ubuntu or Debian, type: |
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The upstream git repository for it is in the olpc-contrib repository located here: |
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[http://dev.laptop.org/git/activities/olpc-contrib/ olpc-contrib] |
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To use the script you must first install pyserial. '''You must be online when running (any of) the three following commands:''' |
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For Ubuntu or Debian: |
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sudo apt-get install python-serial |
sudo apt-get install python-serial |
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For Fedora, such as on an XO |
For Fedora, such as on an XO, type: |
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sudo yum install -y pyserial |
sudo yum install -y pyserial |
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Wait for the install to complete. |
Wait for the install to complete. |
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Then download and install d6.py |
Then download and install d6.py, type: |
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wget --timestamping http://dev.laptop.org/~rsmith/d6.py |
wget --timestamping http://dev.laptop.org/~rsmith/d6.py |
||
Connect |
Connect a [[Serial adapters|serial adapter]] between the bricked XO (serial end of the cable) and the debricker computer (USB end of the cable). Then on the debricker computer type: |
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python d6.py |
python d6.py |
||
The script will search for the first USB serial port on the system that is available for use. (If your serial connection for the XO is not on the first available port then either modify the script to look for the other port first or open the other serial port with another program so its not available for use by d6.py.) |
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Or if d6.py has been marked executable then you can execute it directly with: |
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./d6.py |
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Once the script is up and running then turn to the bricked XO and power it on. Wait for the script to say it has finished. When it says this, the bricked XO is repaired, and you can disconnect and test. |
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The script will search for the first serial port on the system that is available for use. If your serial connection for the XO is not on the first available port then either modify the script to look for the other port fist or open the other serial port with another program so its not available for use by d6.py. |
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The bricked XO will have been unlocked. |
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Once the script is up and running then connect up a bricked XO and power it on. When the screen on the bricked XO lights up, or you hear the startup sound, it's finished (debricked!) |
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The date and time on the bricked XO will have been set to the date and time on the debricker. |
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To prevent the problem from returning, upgrade to the latest firmware. See [[upgrading firmware]]. |
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= Reproducing = |
|||
How to reproduce the problem, or test for it in different firmware versions: |
|||
* [[Disassembly|disassemble]] the laptop to expose the motherboard, |
|||
* connect a [[Serial adapter|serial adapter]] and a terminal, and test it by turning on the laptop, |
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* turn off the laptop, |
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* remove DC power cable and battery, |
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* disconnect the clock battery, |
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* wait a short time (four seconds on XO-1, 15 seconds on XO-1.75 and XO-4), |
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* reconnect the clock battery, |
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* insert DC power cable, |
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* turn on the laptop, |
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* note the response, (e.g. ''RTC cleared''), |
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* turn off the laptop, |
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* repeat the test with various alternate conditions. |
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= Measuring Charge Current = |
= Measuring Charge Current = |
||
To measure charge or discharge current of the |
To measure charge or discharge current of the clock battery, locate the series resistor from the following list, then use a multimeter to measure the voltage across the resistor. Use Ohms Law to calculate the current. |
||
* XO-1, R250 100 ohms for discharge, R275 1k for charge, see [[Media:XO-1-C2-REV-J-R250-R275.jpg|photograph]], |
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* XO-1.5, R309, 1k, |
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* XO-1.75, R35, 1k 1%, |
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* XO-4, R359, 1k 1%, see [[Media:XO-4-C1-REV-D-R359.jpg|photograph]]. |
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= See Also = |
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* [[/Background|How the clock and battery work together]], |
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* XO-1, R250 100 ohms for discharge, R275 1k for charge, |
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* [[Oatstime]], a tool for use by deployments in setting the clock on a large number of laptops, |
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* XO-1.5, R309, 1k |
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* [[Reuse checklist|Refurbishing & Reuse Checklist]], |
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* XO-1.75, R35, 1k 1% |
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* [[XO Troubleshooting Guide]]. |
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[[Category:HowTo]] |
[[Category:HowTo]] |
Latest revision as of 05:28, 2 January 2014
How to fix an XO laptop suffering from problems with the Real Time Clock (RTC, or clock). If the laptop has security enabled, this problem may prevent booting, usually with the error "Invalid System Date".
Problem Description
Laptops with this problem show one of these symptoms:
- The laptop screen lights up and shows "Invalid System Date" and then powers off, or continues to boot, seeking an activation lease. Activating the laptop will result in the laptop working temporarily, but returning to the same problem on next boot. Affects XO-1, XO-1.5, XO-1.75 and XO-4.
- The power LED turns on, but the screen never turns on (not even the backlight). The microphone LED may flash briefly, but stays off. This symptom can only happen with very old versions of firmware (Q2D05 and Q2D06). Affects XO-1 only.
- The power LED turns on for only about 0.8 of a second, then turns off, and the screen never turns on. Affects XO-1 only.
- The boot animation never stops. Affects 12.1.0 and 13.1.0 only.
Diagnosis
These symptoms are caused by bad date information stored in the clock.
Cause
The following diagram shows the causes of the problem. The colours have meaning:
- blue boxes are possible signs, symptoms, or observations,
- green boxes are deduced causes, or diagnosis,
- red boxes are the resultant problems.
There are several causes:
- The clock lost all power, which is by far the most common cause. The clock has a "coin cell" battery (ML1220) that powers the clock when the AC and the main battery are not present. Power may have been lost because:
- The battery discharged during storage. This is common.
- Some of the early production XO-1 laptops were made with a defective holder for the clock battery, which can come loose or even pop out during normal handling.
- Leakage from the battery, causing corrision, a loss of contact between the battery and the metal contacts inside the holder. Some photos here.
- The clock battery ceased to work.
- The factory did not set the date. This is rare.
- The user set the date to an incorrect value, either by mistake or as an attempt to defeat activation security. This is also rare.
See background for how this works.
Root Cause
This is a firmware bug. The problem is fixed in the latest firmware, compare the diagram above to the new diagram below, which shows how the latest firmware will respond:
For laptops without a lease, they will boot normally with the date set to 2013. For laptops with a lease, they will boot seeking a new lease from the school network.
However, the bug strikes before the firmware checks for a new version, so you must repair.
Repair
The repair process is:
- check the battery and holder,
- set the clock,
- upgrade the firmware,
- charge the clock battery, and;
- check the clock is set after removing power.
Here are English and French diagrams of the process:
English | French |
---|---|
Check the battery and holder
To access the clock battery, remove the main battery, and power cable, and follow the instruction for removing the back cover.
XO-1
Examine the battery and its holder. Is there any sign of acid leakage? Can the battery move in its holder?
On newer models of the XO-1, the clock battery and its holder may be covered by a circular strip of rubber to try to fix this. You can remove this cover by peeling it off.
Remove the battery from the socket, by prying underneath with a plastic tool. (Just removing the battery will fix symptom #3, when the power LED turns on for under a second). Check for signs of leakage underneath the battery, in the holder, and on the motherboard and components around the battery holder.
If there are signs of battery leakage:
- Remove the leaking clock battery and discard it.
- Carefully clean any leakage/corrosion in the battery holder, using e.g. a damp toothbrush.
- Neutralize the leakage/corrosion area with some baking soda.
- Using a magnifying glass, look for damage to surrounding components or electrical tracks
- If present, you are advised to treat the motherboard as broken or dead-on-arrival.
- Obtain a replacement cell battery (these parts are very standard) and install in the socket.
- Any decent electrical/DIY store will stock these, they are known as ML1220 batteries and commonly found in calculators.
- (Never use CR1220; they are not designed to be recharged, will not run the clock for very long, may leak, and may erupt in fire.)
If the battery does not fit well in the socket, carefully examine the shape of the socket. Early laptops had a defective battery holder, pictured here. The photos do not make the problem very obvious; the issue is that the shape of the battery holder does not 'grip' the battery. In other words, a side angle view of the battery holder should be shaped like this:
(_____)
However, the shape of the defective units is more like:
\_____/
(these crude diagrams are exaggerated)
If your XO has a defective holder, you must re-seat the clock battery and secure it so it doesn't come out again. This can be done by putting a drop of glue where the battery contacts the holder, away from the metallic contact.
- The best glue that Mitch has found for this purpose is clear solvent-based household cement. Technically, it is "nitro cellulose" cement. It is also known as "model airplane glue", marketed under various trade names such as "Duco Cement", "Tarzan's Grip". Loctite "Stik'n Seal", etc (Alleskleber, in Germany, maybe?). The solvent in this kind of cement is toxic and flammable, so keep it away from children!
- Stronger adhesives like epoxy or cyanoacrylate (super glue) would probably work too, but it might be difficult to remove the battery later without damaging the holder.
- Don't use "Gorilla Glue"; that's polyurethane, which foams as it cures.
- Don't use RTV silicone; the common variety releases corrosive acetic acid as it cures - if it smells like vinegar, don't use it on electronics.
- Don't use hot melt glue; because it doesn't stick very well to these materials.
- Ordinary "white glue" (PVA, or polyvinyl acetate) will probably work, but it flows easily and goes down underneath the battery - perhaps okay if you are careful not to use too much.
If your XO had a black rubber strip covering the battery in the holder, install the cover again now.
XO-1.5
On the XO-1.5, the clock battery is not in a holder. The battery is encased in shrink tubing, and connected to the motherboard with a short cable. (Eliminating the socket was an attempt to reduce the number of socket issues experienced on XO-1.) The battery, in its protective tubing, is stuck down to the motherboard to prevent it from moving around.
Even though the same standard ML1220 is used, replacing the battery alone is difficult. The shrink tubing will be destroyed as you open it, and it will be difficult, and perhaps even dangerous, to reconnect the wires to a replacement battery.
- It may be possible to repair the tubing with some tape, or to discard the tubing and create your own enclosure with some electrical tape.
- The battery shipped in the laptop is a leggy battery - it has the wires spot-welded to the battery during fabrication. It is a very bad idea to attempt to solder wires to a new battery (it can explode). It is far better purchase leggy replacement batteries (e.g. here, maybe).
If available, one could also take the entire component (connector + cable + tubing + battery) from another laptop, or from a spare parts supply sourced from OLPC.
XO-1.75
See above, the same battery, packaging, and wiring is used as in the XO-1.5.
XO-4
See above, the same battery, packaging, and wiring is used as in the XO-1.5.
Set the clock
There are several methods to fix the clock, depending on the symptoms:
- if the screen turns on and you can boot into Linux, the easiest situation, which happens if the laptop has activation security disabled, or the laptop without a date is able to retrieve an activation lease,
- if the screen turns on but you cannot enter Linux, the next easiest,
- if the screen does not turn on, the worst situation, the power LED will be on, but a bug will stop the firmware before it turns on the screen, or;
- if the screen does not turn on and nor does the power LED.
The clock must be set to the Coordinated Universal Time value, rather than your local time.
(The numbers in some of the commands below are the time and date in UTC (2024-08-25 10:34:34), but in reverse order; second, minute, hour, day of month, month, and year. When you visited this page, our Wiki server used it's own clock to generate this command for you.)
If the screen turns on and you can boot into Linux
In this situation, you must boot Linux, login at a root terminal (e.g. the Terminal activity, or press Ctrl+Alt+F2 to get to the Console).
Set the system time, type:
sudo date --utc --set="2024-08-25 10:34:34"
Then copy the system time into the clock, type:
sudo hwclock --systohc
On XO-1 with releases 12.1.0 and 13.1.0, the above may hang for ten seconds and show a warning "wait for clock tick timed out". The hang and warning may be ignored, the clock will have been set. If you would like to avoid the hang and warning, type:
sudo hwclock --systohc --noadjfile --utc
If the screen turns on but you cannot enter Linux
In this situation, you must use firmware to set the clock:
- disable the security system,
- turn on the laptop and get to the Ok prompt,
- set the clock, type:
select /rtc decimal 34 34 10 25 08 2024 set-time
You can now turn off the machine by pressing the power button for a few seconds.
If the screen does not turn on
In this situation, you must:
- connect a serial adapter to the XO-1 and another computer, see where to connect it,
- use a serial terminal program on the other computer to access the XO-1 via the adapter,
- turn on the XO-1, and you should soon see "Page Fault" on the serial terminal, followed by an "ok" prompt. See /Log/Q2D06 for what it may look like. If you don't see "Page Fault", there are several possibilities:
- if you don't see anything on the serial terminal, either
- the serial adapter is not connected correctly,
- the serial terminal is not configured correctly, see settings, or
- something else is wrong with the XO-1, perhaps it is quite quite dead and it's not an instance of this known clock problem after all.
- if you see a lot of startup messages, and the last one isn't "Page Fault" followed by "ok", then the machine is not suffering from the this known clock problem, but may have a broken display or display cable.
- if you don't see anything on the serial terminal, either
- using the serial terminal, type this command to set the clock:
select /rtc decimal 34 34 10 25 08 2024 set-time
- restart the laptop, type this command:
bye
- check that the screen lights up.
See /Log/Q2D06 for what is expected on the serial terminal.
(There are numerous opportunities for error, so if you have more than one XO-1 laptop practice serial communications with working ones before debugging broken ones).
If the screen does not turn on and nor does the power LED
You must remove the clock battery briefly to fix this problem. If you did that, and the problem persists, then the cause is not the clock. Have the motherboard serviced.
Upgrade the firmware
Upgrade the firmware to make sure this problem does not return. See upgrading firmware for the latest firmware.
If you had the blank-screen problem, the firmware must be upgraded to the latest version. If not, and the clock loses power again, the repair will need a serial adapter again.
If you wish to manually upgrade, and you used a serial adapter and saw the "Page Fault" message, you must probe the PCI and USB before manually upgrading, type:
probe-pci probe-usb flash u:\q2f19.rom
Or set the clock, allow time for the clock battery to charge, and use the usual upgrading firmware method.
Charge the clock battery
Leave the laptop turned on for at least 30 minutes to charge the clock battery to normal levels.
- Half an hour is the minimum charge time before testing, for which you can use the main battery,
- The best charging time is 24 hours before storage, for which you must use a power adapter,
- Charging does not happen with the laptop on and suspended; the power LED must be on and not flashing,
Easiest method is to remove all USB drives, then hold down all four game keys while turning the power on; the laptop will eventually fail to boot and wait for you to Use power button to power off, with the start time displayed in UTC:
Boot failed OLPC C2, 256 MiB memory installed, S/N SHC92805B50 OpenFirmware Q2F19 EC Firmware Ver:1.2.1 2024-08-25 10:34:34 UTC Use power button to power off
Or boot to Ok prompt.
Or boot to Linux and disable automatic power management.
Check the clock is set after removing power
Verify that the laptop is able to retain the time and date, otherwise this problem may return.
- Unplug the charger,
- Remove the main battery from the underside of the laptop, (not the clock battery),
- Leave the laptop without power for five minutes,
- Connect a power source (the battery, or the charger) and turn on the laptop,
- Check the clock using either the Ok prompt or by running date in the Terminal activity.
If the clock is still wrong, then 3 situations are possible:
- The clock battery is faulty and must be replaced.
- You can verify this by installing a known-working battery, reprogramming the clock, and then repeating this verification test. Test pass would confirm this problem.
- There is a problem with the battery holder or the motherboard, so the laptop should be replaced.
- You can verify this by installing a known-working battery, reprogramming the clock, and then repeating this verification test. Test fail would confirm this problem.
- If you are dealing with a defective shape battery holder, perhaps the clock battery is (still) not maintaining electrical contact with the connector inside the battery holder.
Automated repair script
XO-1 only.
Repair center volunteers have made an automated script to repair laptops in bulk or as a method with fewer steps. The script can be run on a Linux computer or on an XO laptop. We call this second computer your "debricker".
To use it you must install pyserial. You must be online when running (any of) the three following commands:
For Ubuntu or Debian, type:
sudo apt-get install python-serial
For Fedora, such as on an XO, type:
sudo yum install -y pyserial
Wait for the install to complete.
Then download and install d6.py, type:
wget --timestamping http://dev.laptop.org/~rsmith/d6.py
Connect a serial adapter between the bricked XO (serial end of the cable) and the debricker computer (USB end of the cable). Then on the debricker computer type:
python d6.py
The script will search for the first USB serial port on the system that is available for use. (If your serial connection for the XO is not on the first available port then either modify the script to look for the other port first or open the other serial port with another program so its not available for use by d6.py.)
Once the script is up and running then turn to the bricked XO and power it on. Wait for the script to say it has finished. When it says this, the bricked XO is repaired, and you can disconnect and test.
The bricked XO will have been unlocked.
The date and time on the bricked XO will have been set to the date and time on the debricker.
To prevent the problem from returning, upgrade to the latest firmware. See upgrading firmware.
Reproducing
How to reproduce the problem, or test for it in different firmware versions:
- disassemble the laptop to expose the motherboard,
- connect a serial adapter and a terminal, and test it by turning on the laptop,
- turn off the laptop,
- remove DC power cable and battery,
- disconnect the clock battery,
- wait a short time (four seconds on XO-1, 15 seconds on XO-1.75 and XO-4),
- reconnect the clock battery,
- insert DC power cable,
- turn on the laptop,
- note the response, (e.g. RTC cleared),
- turn off the laptop,
- repeat the test with various alternate conditions.
Measuring Charge Current
To measure charge or discharge current of the clock battery, locate the series resistor from the following list, then use a multimeter to measure the voltage across the resistor. Use Ohms Law to calculate the current.
- XO-1, R250 100 ohms for discharge, R275 1k for charge, see photograph,
- XO-1.5, R309, 1k,
- XO-1.75, R35, 1k 1%,
- XO-4, R359, 1k 1%, see photograph.
See Also
- How the clock and battery work together,
- Oatstime, a tool for use by deployments in setting the clock on a large number of laptops,
- Refurbishing & Reuse Checklist,
- XO Troubleshooting Guide.