Richard A. Smith
richard at laptop.org
Mon Oct 8 05:58:10 EDT 2012
On 10/07/2012 10:21 PM, Mikus Grinbergs wrote:
> IIRC, Richard warned about connecting an XO's USB socket to any USB
> device where that devices's USB socket can emit power (that sets up a
> condition where a non-XO device can try to send power to the XO --
> which is a no_no).
The details are fuzzy but in Kevin's case I believe he was trying to use
a external CDROM that drew a lot of juice tying to spin up and fail. To
compensate he was connecting one of those rechargeable batteries with a
5V USB output via a Y cable. So now you have 2 power sources fighting
it out on the USB bus and the XO-1.5 would lose.
> So when i plug one usb device into the xo be it an ipod or a cell
> phone while running on battery the screen goes white and the laptop
> reboots. It works fine when plugged in charging though. I just wanted
> to let you all know what im experiencing. I believe the devices are
> drawing too much current from the laptop and forcing a reboot. It
> doesnt matter which usb port i plug it into.
What production rev model is your 1.5? Did you get it from the
developer program? I have a vague recollection that some of our earlier
runs of 1.5 had a USB issue like that.
Richard A. Smith <richard at laptop.org>
One Laptop per Child
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