XO Troubleshooting PowerOn

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HowTo [ID# 142323]  +/-

This is the portion of the XO Troubleshooting Guide for diagnosing problems turning on an XO laptop.

Welcome

For an introduction to the different boot options selectable while powering on, see the Cheat codes.

All of these tests assume that two known good sources of power are available: a charged battery and a power adapter. To debug problems with the power source, and battery charging issues, see Power and Battery problems.

Regularly test that both the power adapter and battery used in these tests are working. This may be done easily using another laptop. A laptop may be unable to power itself from its battery or power adapter (for a number of reasons).

Start by pressing the power button for a second.

Does the Power LED turn on ?

When the power button is pressed once, and the power LED doesn't turn on, verify the following:

Please try resetting the Embedded Controller. Pay attention to the battery LED when power is first reapplied. It should flash orange momentarily (about a quarter of a second). If it does not flash, then the Embedded Controller is not operating properly, and the motherboard should be replaced.

In these cases, the Embedded Controller Flash chip should be replaced as the first attempt to repair the motherboard. See replacing the embedded controller flash.

If the power LED doesn't turn on, but the laptop proceeds to illuminate the backlight and even boot, the problem may be either the LEDs themselves or the power LED driver (Q39, DDTC144EUA). The LEDs are in series, so if one fails they may both fail to light.

On rare occasions, the power button becomes stuck mechanically. In this case, the laptop does not detect the depression of the power button, and does not turn on. Ensure that the power button is moving freely.

Insert photo of 'stuck' power button vs. 'unstuck' power button

If the battery LED flashed on restoration of power, the power button isn't stuck, and no other signs of life are detected, then the failure mode is unknown. Replace the motherboard to repair.

Does the display activate ?

The power LED indicates that the Embedded Controller has enabled the power to the CPU. Open Firmware (OFW) begins executing. The next visible step is turning on the display. The LCD display should be initialized with white, then begin to show text or graphics. The backlight for the screen should be turned on, even if the backlight was previously turned off.

If this does not happen then the boot sequence may not be reaching Open Firmware, or OFW may be crashing early in the boot process. The way to tell is to look at the Microphone activity LED. The default state of the microphone LED is lit. One of the first steps Open Firmware does is to turn off the microphone LED. If the power LED and the microphone LED are both lit then a serious boot error has occurred and the motherboard needs replacing.

Did the boot sound play ?

Boot sound does not play

This usually indicates a broken motherboard or a Real Time Clock battery problem in conjunction with early firmware. Some machines in our early production runs (before Jan. 2008) both had a problem with the Real Time Clock battery holder and had a version of Open Firmware (earlier than Q2D07) which locked up when it encountered a reset clock. The problem and its solutions are discussed elsewhere.

Boot sound plays

If the display doesn't initialize, but the boot sound plays, then this is probably a problem with the display. See Display Problems.

Laptop boots normally, but no boot sound plays

If no boot sound is played, but the machine boots normally and has audio, it is possible that the user has changed the default boot volume to 0. While the boot sound is playing, a user can adjust the volume using the volume adjust keys. This modified volume setting is saved and used for future boots. Try increasing the volume right after starting the laptop a few times, and see if the boot sound returns.

If no boot sound is played, and the machine boots normally but has no audio see Audio Problems.

The display remains blank

The display is active (including backlight), but no text or graphics appear.

This is typically a problem with the Embedded Controller's Flash ROM. It can be caused by removing power to a laptop while it is upgrading the firmware. In the field, the motherboard should be replaced.

This diagnosis may be verified by connecting to the processor serial port (J1) and watching the early Open Firmware boot process. In some cases, it may be possible to manually reprogram the EC Flash from a USB key. In other cases, the EC Flash will have to be replaced.

The display says "Connect to power to proceed"

Not quite the correct wording. Anyone remember the exact words ?

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 ( Trac ticket #5422). If this is the problem, provide both sources of power and reboot. The laptop should proceed with a firmware update and boot normally.

The display is showing an XO icon

This means that Open Firmware has started the boot process.

You can see much more information from Open Firmware by holding the '✓' (check) button (above the power button) after powering on. That will make Open Firmware display more detailed messages about what it is doing during the secure boot process (including early boot messages from the Linux kernel). The messages are in English only.

XO icon 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 solution is to re-activate the laptop. Obtain a copy of the lease (or a new lease) from your country activation manager, place it (named "lease.sig") on the root directory of a USB key and boot the laptop. See what to do with your activation keys.

XO icon with a "sad face"

This means that Open Firmware couldn't find a signed operating system on the internal flash memory. (It will also look on USB memory sticks and SD cards.)

Try upgrading or re-installing the software.

XO icon 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, it means that something is wrong when the Linux operating system starts operation.

This happens for a number of reasons, such as NAND Flash being full (Trac ticket #5317), user "interaction" with the operating system or a hardware problem with the NAND Flash ROM. The suggested solution to try is upgrading or re-installing the software.

If this has happened to the same laptop more than one time, it may have a Flash block that has gone bad.

Dealing with Bad Blocks on NAND

If you suspect that some NAND FLASH blocks have gone bad and you have a developer's key, you can ask Open Firmware to check the NAND FLASH and add newly-bad blocks to the "bad block table" that tells the system not to use them.

If you are using Open Firmware Q2D16 or earlier, the procedure requires that you type a few lines because of a firmware bug:

 ok dev /nandflash
 ok : xx dup aa ;
 ok patch xx aa full
 ok dend
 ok test /nandflash::fixbbt

If your Open Firmware is newer than Q2D16, you don't need the first 4 lines; just type the line that begins with "test".

This procedure takes several minutes, because it tests every block on the NAND FLASH with several data patterns. The procedure is "safe" for good NAND FLASH, because it saves the previous block data before the test and restores it afterwards, so you won't lose any data on good FLASH blocks. There is, however, a small chance of data loss in the event that a block goes bad during (i.e. as a result of) the test, preventing restoration of the previous contents.