Memory replacement

Kevin Gordon kgordon420 at
Wed Mar 9 11:31:24 EST 2011

Mikus and James and the gang:

OK, the little 8GiB microSD card inserted into an SD adapter, inserted into
the external SD slot, passed the dir test that James said to perform at
OFW.  Didnt complain.  However, it is a "Class 2" Sandisk card, so it might
not really be the right way to go.  Before I do the surgery, armed with
silver heat sink paste, and being very careful about pressure on the m/b,
and having my anti-static wrist guard properly attached - advice please: go,
no-go, spend the extra pennies and get a Class 4/6/8/10.  All I know for
sure is the 2GiB card in there has to be replaced.  There are progressively
more and  red squares appearing on every refresh, and since this is a
'contributors machine' that I screw up regularly testing a billion USB
contraptions, I reload almost every day that I use it :-)

Thanks gents.


On Sun, Mar 6, 2011 at 4:06 PM, Mikus Grinbergs <mikus at> wrote:

> > how to upgrade the SD card ?
> All you have to do is "stick the new card in", then perform the
> 'fs-update' (with an appropriate-sized .zd image).  The ENTIRE
> SD-card-content will be written-over-anew, including the partition table.
> ----
> The catch is that the micro-SD card is beneath the heat spreader - and
> once you replace the card, you have to make sure that the heat spreader
> has thermal contact with the CPU chip.  [I suspect that "too much
> physical pressure at the CPU chip" might have contributed to the #10314
> failures of some pre-production XO-1.5 motherboards.]
> ----
> > a fresh new 8GiB micro-SD card
> I had good luck with a 8GiB micro-SD card in the 2009 XO-1.5 I had (but
> that system eventually stopped working - I don't know if my having put
> in a different micro-SD card had any relationship to that failure).
> What appears to matter most with the micro-SD card is its SPEED (it
> would take a heck of a lot of Journal entries to fill even a 4GiB card).
>  There was a discussion on the devel list a long while ago about the
> transfer speeds measured on the XO-1.5 with several different cards --
> apparently NOT ALL the available cards met OLPC reliability specs.
> mikus
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