XO battery/performance [Devel Digest, Vol 76, Issue 4]

Richard A. Smith richard at laptop.org
Sun Jun 3 08:41:03 EDT 2012

On 06/03/2012 04:43 AM, Yioryos Asprobounitis wrote:

>> serial connector loaded.  Its
>> the connector under the heat spreader.
> There goes my new XO-1.75...

Think of it a a rite of passage.

> Just to be sure, is the UART 4, CN23, shown in the attached picture in blue. Correct?


> If OK, please advise further actions.

First upgrade the firmware to the latest version and let it update the 
EC code.

Then just plug up the serial connector and then do a full power cycle of 
the unit by removing both external power and the battery and then 
plugging in the problem battery.  Send the output.  May or may not be 
anything of interest in that log.

Then see if the problem duplicates on the 1.75.  You can get a quick 
reading from the EC of the battery level by using the command 'b3'. 
Type b3 <enter> which turns on some simple debug info.  You can't leave 
that on however because it will prevent the EC from going into stop 
mode.  'b0' will turn it back off.

You have to be really quick with the serial commands when the XO is off. 
  When off and running on battery the EC will go into stop mode and it 
does that really fast.  When its in stop mode you can't talk to it on 
the serial port.    I usually have one hand ready to type b3 and then 
wake the EC up by a very short power button press.  Then before it goes 
back into stop mode type b3<enter>.  Once a second it will output a 
short battery stat then type b0 to stop it and allow it to go back into 
stop mode.

So hook up the EC serial port and log the output. Then charge up the 
battery. b3 to get some readings. Disconnect external power and then b0 
.  You should see it go into stop mode.   In 24 hours wake the EC up do 
b3 to get a 2nd set of readings and then send the log output.

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

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