EC corruption by q2f04rc firmware

Richard A. Smith richard at
Tue Oct 25 22:03:40 EDT 2011

On 10/23/2011 05:50 PM, Kevin Gordon wrote:

> It appears that the battery is not recharging when the A/C is plugged
> in.  I've tried two different batteries, and they drain to flashing red,
> even when the plug is in.  Reverting to Q2E48 seems to have fixed that
> behaviour.  I will continue testing.

Flashing red indicates an error. If you get flashing red then the 
battery subsystem is halted.

Stop at OFW run 'watch-battery' and then press a key to exit.
watch-battery will tell you what the error is.

Making an educated guess I'd say your error source is EEPROM corruption 
caused by ESD.  The new code backported from 1.5 detects this condition. 
  If its caught early then the code can prevent it from getting 
committed into the EEPROM but it can't fix it if its already committed.

Since charging works on XO-1 your EEPROM(s) are not corrupted so bad 
that it fatal. However, if you are getting corruption then its a not a 
matter of 'if' but 'when' until you hit the bits that will break your 

You can dump the battery EEPROM with 'bat-dump-banks' and take a look. 
You should not see a long series of 0xff or 0x00 in the data.

Richard A. Smith  <richard at>
One Laptop per Child

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