XO 1.75 11089 Fix: Difference between revisions
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# [[Disassembly_top|Disassemble the laptop]] to access the motherboard (the heat spreader does not have to be removed). |
# [[Disassembly_top|Disassemble the laptop]] to access the motherboard (the heat spreader does not have to be removed). |
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# Plug in a serial cable (see [[#Finding_the_Serial_Port|below]], and a USB key with Q4B06 or later. |
# Plug in a serial cable (see [[#Finding_the_Serial_Port|below]]), and a USB key with Q4B06 or later. |
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# 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 [[User:wad|wad]]. |
# 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 [[User:wad|wad]]. |
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# Type "dir u:" to initialize the USB stack. |
# Type "dir u:" to initialize the USB stack. |
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Revision as of 17:27, 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:
