XO 1.75 11089 Fix

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Revision as of 00:50, 5 August 2011 by Wad (talk | contribs) (→‎The Fix)
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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):

  1. Disassemble the laptop to access the motherboard (the heat spreader does not have to be removed).
  2. Plug in a serial cable (see below, and a USB key with Q4B06 or later.
  3. 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.
  4. Type "dir u:" to initialize the USB stack.
  5. Type "flash! u:\q4b06.rom". When the laptop finishes reflashing and returns an ok>, either reboot (type "bye") or poweroff the laptop.

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:

1.75 serial connector.png
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