[olpc-help] RTC Battery

Steve Holton sph0lt0n at gmail.com
Wed Jun 4 16:10:22 EDT 2008

On Wed, Jun 4, 2008 at 3:54 PM, Richard A. Smith <richard at laptop.org> wrote:
> Caryl Bigenho wrote:
>> I have hunted all over the wiki and forum for instructions for
>> de-bricking.  I noticed you posted a good set on the OLPC forum back in
>> Feb or so. That is why I am asking you...
> http://en.forum.laptop.org/viewtopic.php?f=2&t=430&p=533274#p533274
>> 1) Where on the wiki or anywhere else is there a picture of the RTC
>> battery or a schematic showing exactly where it is located?

The best image I've found is at:

But this is an earlier prototype board.
On this board, the RTC battery is mid center at the bottom. It is a
silver circle. It's a button cell (like a watch or camera battery) and
it's in a plastic 4-prong holder.

On the G1G1 version XO's it's not in the same place (I don't think)
but it's the same relative size, etc.

> But any 3.3V TTL to rs232/USB will work.
... with the proper connector.

>> 3) Did I read that this can be done by soldering instead?  That might be
>> easier than trying to find the right kind of adaptor.

> Sure if you remove the SPI flash and solder on a new one or pop it in a
> programmer and re-program it with firmware that does not page fault on
> bad RTC data.  You need to be familiar with SMT rework and have the
> proper tools.

You don't want to pursue this unless you already have (or are willing
to make an investment to get) the right equipment and skills.  For
this particular problem, the serial cable is the way to go.

Steve Holton
sph0lt0n at gmail.com

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