XO 1.75 11089 Fix: Difference between revisions
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# Type "dir u:" to initialize the USB stack. |
# Type "dir u:" to initialize the USB stack. |
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# Type "flash! u:\q4b06.rom". When the laptop finishes reflashing and returns an ''ok>'', either reboot (type "bye") or poweroff the laptop. |
# Type "flash! u:\q4b06.rom". When the laptop finishes reflashing and returns an ''ok>'', either reboot (type "bye") or poweroff the laptop. |
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# [[Disassembly_top#Replacing_the_back_cover|Reassemble]] |
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===Finding the Serial Port=== |
===Finding the Serial Port=== |
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Revision as of 00:52, 5 August 2011
This page is monitored by the OLPC team.
Version Q4B05 of Open Firmware for the XO 1.75 B1 laptop had a bug (<trac>11089</trac>) which causes the laptops to boot up with a white screen if it has been ten days since their manufacture, or if the RTC battery is removed. The symptom is a white screen (nothing on it) on boot.
The Fix
Fortunately, the fix to this is simple (yet tedious):
- Disassemble the laptop to access the motherboard (the heat spreader does not have to be removed).
- Plug in a serial cable (see below, and a USB key with Q4B06 or later.
- Boot the laptop. It should print out a boot sequence on the serial port, ending in Unrecognized SPI Flash ID. It should then provide an ok> prompt. If at this point, it stops somewhere else or doesn't provide a prompt (like after Releasing) you have another problem. Please contact wad.
- Type "dir u:" to initialize the USB stack.
- Type "flash! u:\q4b06.rom". When the laptop finishes reflashing and returns an ok>, either reboot (type "bye") or poweroff the laptop.
- Reassemble
Finding the Serial Port
You will need an XO serial adapter. The serial port to use is UART3 (CN8). There is a chart showing the location, and this photo:
