XO Troubleshooting Guide: Difference between revisions

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{{OLPC}}{{Translations}}__NOTOC__
This is a troubleshooting guide for the [[Hardware_specification#Laptop_Hardware|XO laptop]]. It is geared toward troubleshooting production units running firmware version Q2D03 or greater.
This is a troubleshooting guide for the [[Hardware#XO_Laptop|XO laptop]].
While this is intended for use in a repair center, most of the procedures can be followed by users to [[Repair|repair]] their laptops.


==Powering on==
''Still very much a work in progress!! Feel free to add''
If you are having problems getting the XO to power on, see [[XO_Troubleshooting_PowerOn|Troubleshooting Power On]]. The [[Startup Diagnosis]] page also describes how end users (not repair centers) can debug power-on or boot problems.


==Display==
=Problems powering on=
If you are having problems with the display on an XO laptop, see the [[XO_Troubleshooting_Display|Display diagnostics section]].


==Power and Battery==
For an introduction to the different boot options selectable while powering on, see the [[Cheat codes]].
If you are having problems such as:
* the battery is not charging
* the battery is suddenly losing charge
* the laptop won't run from a power adapter


Then you should view:
All of these tests assume that a known good source of power is available, either a charged battery or power adapter. To debug problems with the power source, and battery charging issues, see [[#Power_and_Battery_problems|Power and Battery problems]].
* [[XO Troubleshooting Battery]], if you believe the problem is contained within the battery itself, or
* [[XO Troubleshooting Power]], if you believe the problem is contained within the laptop (e.g. charging circuitry, power input circuitry), or
* Both of the above, if you are unsure where the problem is localised.


==Network==
==Is the Power LED On ?==
If your laptop is having trouble connecting to other laptops or the Internet, see the [[XO_Troubleshooting_Network|Network diagnostics section]].


==Audio and Camera==
When the power button is pressed once, the power LED doesn't turn on.
If you are having problems with the audio (microphone, speakers, headphones, or microphone input) or camera on an [[Hardware#XO_Laptop|XO laptop]], see the [[XO_Troubleshooting_AV|AV diagnostics section]].


==Keyboard and Touchpad==
Please try [[#Rebooting_the_Embedded_Controller|Resetting the Embedded Controller]].
If you are having problems with the keyboard or touchpad on an XO laptop, see the [[XO_Troubleshooting_Keyboard|Keyboard diagnostics section]].
==Touchscreen==


See the [[XO_Troubleshooting_Touchscreen|Touchscreen section]].
==Does the display light up ?==


==USB==
When the power button is pressed once, the power LED turns on, but the
If you are having problems with the USB interfaces on an XO laptop, see the [[XO_Troubleshooting_USB|USB diagnostics section]].
screen doesn't light up


==Debugging Procedures==
==Does the boot sound play ?==
The following are common debugging and test procedures:


* [[XO Full Reset|Rebooting the Embedded Controller]] - This completely resets a laptop
If no boot sound is played, but the machine boots normally, see [[#Audio_problems|Audio Problems]].
* [[XO_Self_Test|Hardware Self-Test]] is included in the [[Hardware#XO_Laptop|XO laptop]].
* [[Cheat codes|Boot options]] - Different boot options are available through pressing buttons around the screen during the initial boot process (immediately after pressing the power button). A sampling (more at [[Cheat codes]]):
** '✓' (check) game pad key: forces a more detailed display while booting. See [[XO_Troubleshooting_PowerOn#The_display_is_showing_an_XO_icon|Troubleshooting Power-On]] for more details. This is useful for debugging activation problems.
** 'O' game pad key: alternate between the current boot image and a previous one. In laptops which have never been upgraded, there is no previous boot image to use.
** Rocker left: run the [[XO_Self_Test|hardware self-test]].
* A [[Serial_adapters|serial adapter]] is very useful for debugging dead laptops


==Repair Procedures==
== The display says "Connect to power to proceed" ==
The following are common repair procedures:


* [[Reuse checklist|Summary Refurbishing & Reuse Checklist]]
'''Not quite the correct wording. Anyone remember the exact words ?'''
* [[Motherboard Handling Procedures]]
* [[Disassembly|Disassembly Guide]]
** [[Disassembly_top|Getting at the display and motherboard]]
** [[Disassembly_bottom|Replacing a keyboard/touchpad]]
** [[Screws|Guide to screws]]
* Motherboard Guides: [[XO Motherboard|intro]], or [[XO_Motherboard_Repair|repair]]
* [[Activation_and_Developer_Keys|Getting a developer key for a laptop]]
* Using an XO as a serial terminal on either [[Serial_adapters#Linux|Linux]] or [[Firmware/Serial_Terminal|Open Firmware]],
* [[XO_Flash_Bad_Blocks|Finding and fixing bad blocks of NAND Flash]]
* [[SPI_FLASH_Recovery|Replacing/Recovering the EC (SPI) Flash]] - Replacing the [[Embedded_controller|Embedded Controller]] Flash
* [[Fix_Clock|Fixing an RTC problem]] - Fix laptops which can't boot due to reset RTC time.
* [[XO_LiFePO4_Recovery_Procedure|Fixing LiFePO<sub>4</sub> batteries that stop charging]]
* [[XO_Power_Diagram|A detailed description of the laptop power circuitry (XO-1)]]
* [[Memory Bit Mapping]]


[[Category: Repair]]
Early versions (before Q2D14) of the firmware would stop execution if a firmware update was scheduled, but two sources of power (a battery and a power adapter) aren't present (
[[Category: Hardware]]
[[http://dev.laptop.org/ticket/5422|Trac #5422]]). If this is the problem, provide both sources of power and reboot. The laptop should proceed with a firmware update and boot normally.
[[Category:XO-1]]

[[Category:XO-1.5]]
==The display is showing an XO icon==
[[Category:XO-1.75]]
This means that Open Firmware has started the boot process.
[[Category:XO-4]]

[[Category: Developers]]
===with a single dot below it===
If laptops powers up, but stops when just displaying the XO icon in the middle, with a single dot below it...

"sad face" if it can't find a signed operating system on the internal flash memory. (It will also look on USB memory sticks and SD cards.) If your laptop does this, and you don't have anything important stored on the laptop, I suggest doing a full reflash using the Activated Update procedure. That should fix the "sad face".


===with a serial number and three icons below it===
If the laptop powers up, but stops when displaying the XO icon in the middle of the screen, followed by a serial number (e.g. CSN74902B22) and three icons (SD disk, USB disk, Network signal strength), it is looking for its activation lease. This should eventually print "Activation lease not found" at the top of the screen and power-off soon thereafter.

==The laptop is failing activation==


The solution is to

=Display problems=

==One half of the display looks bad==

==The display fades to white==

==The backlight won't turn on==



==The backlight isn't even==

In this case, a vertical pattern of light and dark is seen on the display. The difference between light and dark regions being strongest at the bottom of the screen.

===Is the backlight cable properly connected ?===
Disassemble the laptop to access the small flex cable from the display to the motherboard. Make sure that it is properly seated in its connector, and properly clamped down.

''Photo needed here, a closeup of the backlight connector''

If the connector is broken (the small black tab fails to stay in place), the motherboard will need replacement.

A temporary solution is to wind a small strip of paper several times, jamming a small piece of it into the connector to hold the flex cable in place. A piece of tape covering the connector provides additional stability.

===Is the lightbar broken ?===
If the cable is well seated, then it is likely that the actual lightbar in the display has failed. This lightbar can be replaced (the display itself is probable fine.)

===Is the motherboard backlight driver broken ?===
If replacing the lightbar fails to correct the problem, it is a motherboard problem. Check the voltages across R147, R148, and R149 when the backlight is operating. They should be equal. If they are not, replace the corresponding switch transistor (Q13, Q14, or Q15, respectively) with a generic NPN low power switching transistor (2N3904).

=Audio problems=


=USB problems=

==One of the USB ports doesn't work==

==None of the USB ports work==


=Power and Battery problems=

== The laptop won't run using the battery ==
== The laptop won't run using the power adapter ==
== The laptop emits a high pitched whine when using the power adapter ==
== The laptop can't charge the battery ==

=Common Procedures=
==Rebooting the Embedded Controller==
The XO embedded controller (EC) occasionally becomes confused. To reset it, remove all power sources from the laptop:
# Take the battery out and remove the power adapter
# Wait 10 seconds to allow the embedded controller to lose power and reset
# Replace at least one source of power (battery or power adapter)

The battery LED should flash orange momentarily (about a quarter of a second) when power is first reapplied. If you do not see this flash, you either have a motherboard hardware problem or faulty EC firmware installed. The general solution to both of these problems is to replace the motherboard.

==Boot options==
Different boot options are available through pressing buttons around the screen during the initial boot process (immediately after pressing the power button).

* '✓' '''(check) game pad key:''' forces a more detailed display while booting. See [[Startup Diagnosis]] for more details. This is useful for debugging activation problems.
* 'O' '''game pad key:''' alternate between the current boot image and a previous one. In laptops which have never been upgraded, there is no previous boot image to use.
* '''Rocker left:''' invoke laptop diagnostics. If using firmware later than Q2D08, you can pause between individual tests by holding down the "rotate" button. This is useful in debugging motherboard, audio, camera, USB, keyboard and touchpad problems.

These are included here for completeness. More information is available at [[Cheat codes]].

==Reloading the Software==

Latest revision as of 05:09, 28 October 2013

  This page is monitored by the OLPC team.
  english | español HowTo [ID# 293344]  +/-  

This is a troubleshooting guide for the XO laptop. While this is intended for use in a repair center, most of the procedures can be followed by users to repair their laptops.

Powering on

If you are having problems getting the XO to power on, see Troubleshooting Power On. The Startup Diagnosis page also describes how end users (not repair centers) can debug power-on or boot problems.

Display

If you are having problems with the display on an XO laptop, see the Display diagnostics section.

Power and Battery

If you are having problems such as:

  • the battery is not charging
  • the battery is suddenly losing charge
  • the laptop won't run from a power adapter

Then you should view:

  • XO Troubleshooting Battery, if you believe the problem is contained within the battery itself, or
  • XO Troubleshooting Power, if you believe the problem is contained within the laptop (e.g. charging circuitry, power input circuitry), or
  • Both of the above, if you are unsure where the problem is localised.

Network

If your laptop is having trouble connecting to other laptops or the Internet, see the Network diagnostics section.

Audio and Camera

If you are having problems with the audio (microphone, speakers, headphones, or microphone input) or camera on an XO laptop, see the AV diagnostics section.

Keyboard and Touchpad

If you are having problems with the keyboard or touchpad on an XO laptop, see the Keyboard diagnostics section.

Touchscreen

See the Touchscreen section.

USB

If you are having problems with the USB interfaces on an XO laptop, see the USB diagnostics section.

Debugging Procedures

The following are common debugging and test procedures:

  • Rebooting the Embedded Controller - This completely resets a laptop
  • Hardware Self-Test is included in the XO laptop.
  • Boot options - Different boot options are available through pressing buttons around the screen during the initial boot process (immediately after pressing the power button). A sampling (more at Cheat codes):
    • '✓' (check) game pad key: forces a more detailed display while booting. See Troubleshooting Power-On for more details. This is useful for debugging activation problems.
    • 'O' game pad key: alternate between the current boot image and a previous one. In laptops which have never been upgraded, there is no previous boot image to use.
    • Rocker left: run the hardware self-test.
  • A serial adapter is very useful for debugging dead laptops

Repair Procedures

The following are common repair procedures:

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