XO 1.75 11089 Fix: Difference between revisions
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(May be the first time some people have to use serial adapters) |
(using flash instead of flash! means we must mention power cable, and so we may as well mention the serial cable as well.) |
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Fortunately, the fix to this is simple (yet tedious): |
Fortunately, the fix to this is simple (yet tedious): |
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# Turn off the laptop, unplug the power cable, but leave the battery inserted, |
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# [[Disassembly_top|Disassemble the laptop]] to access the motherboard |
# [[Disassembly_top|Disassemble the laptop]] to access the motherboard. The heat spreader does not have to be removed. |
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| ⚫ | |||
# Plug the power cable back in, |
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# Attach the serial cable/adapter to another computer, and configure a terminal emulation program on this other computer to access the serial adapter at 115200 baud, 8 bits, No parity, 1 stop bit. |
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| ⚫ | # |
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# Plug in a USB drive with Q4B06 or later, |
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| ⚫ | |||
# Attach the black end of the serial cable to a [[Serial_adapters|serial adapter]], |
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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. |
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# Attach the serial adapter to another computer, |
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# [[Disassembly_top#Replacing_the_back_cover|Reassemble]] |
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# Configure a [[Serial_adapters#Software|terminal emulator]], |
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| ⚫ | # Power on the laptop. It should print out a boot sequence over the serial port, which will be shown by the terminal emulator. The sequence should end 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 "flash u:\q4b06.rom" in the terminal emulator and the laptop will rewrite the firmware and reboot. |
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# Turn off the laptop, remove the serial cable (if it is no longer required), and [[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 00:21, 8 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):
- Turn off the laptop, unplug the power cable, but leave the battery inserted,
- Disassemble the laptop to access the motherboard. The heat spreader does not have to be removed.
- Plug the power cable back in,
- Plug in the white end of the serial cable (see below),
- Plug in a USB drive with Q4B06 or later,
- Attach the black end of the serial cable to a serial adapter,
- Attach the serial adapter to another computer,
- Configure a terminal emulator,
- Power on the laptop. It should print out a boot sequence over the serial port, which will be shown by the terminal emulator. The sequence should end 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:" in the terminal emulator to initialize the USB stack.
- Type "flash u:\q4b06.rom" in the terminal emulator and the laptop will rewrite the firmware and reboot.
- Turn off the laptop, remove the serial cable (if it is no longer required), and reassemble.
Finding the Serial Port
You will need an XO serial adapter designed for use with XO 1.5's or higher (which also work with XO-1's). The serial port to use is UART3 (CN8). There is a chart showing the location, and this photo:
