Attempting to re-purpose former XO 1.5 4GB microSD cards.

Richard A. Smith richard at laptop.org
Mon Sep 17 01:46:48 EDT 2012


On 09/16/2012 09:57 PM, Kevin Gordon wrote:

> Therefore, I fear that I must have been an ESD devil this morning when I
> took the cards out of the machine, and fried them by not taking
> recommended precautions.  I can think of no other plausible reason. But,
> it appears it's just these two cards, and not the process.   Next time,
> no skipping the wrist strap.  Sorry for the bother.
>
> Aaargh .. but thanks again for answering quickly and adding even more
> doisk management  tools to the arsenal.

I doubt it was ESD.  Rather I suspect you were hit with what our 
manufactures called an SPO or sudden power off.  I suspect the card 
power bounced while the FTL was moving some blocks around.  You don't 
actually have to remove the card for this to happen as the power to the 
card socket is software controlled.

We dealt with this numerous times while qualifying SD cards.  The EC in 
the XO keeps the power up on the SD card for several seconds after the 
main power it turned off to help prevent this from happening.

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



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