tiago wrote: > I forgot to mention that's not my case since even if I plug the two USB ends > it still can't power up.
on either XO model the extra cables won't make a difference -- all the power (1A available total) is available to any port. does your drive work on an XO-1? do you have power consumption specs for your drive? paul > > Best regards, > Tiago > > On Sat, Apr 24, 2010 at 7:42 PM, Sameer Verma <[email protected]> wrote: > > > On Sat, Apr 24, 2010 at 4:55 PM, Tiago Marques <[email protected]> wrote: > > > Hi all, > > > I've ran into something on the 1.5 B2 I have here, which I'm in doubt if > > may > > > or may not be relevant for OLPC's hardware people(it seems not), so I'm > > > reporting it anyway. > > > All three USB ports can deliver enough power to an USB 2.5" HDD, no > > problem. > > > They cannot in the following conditions: > > > - An extra SD card is plugged in > > > - Another USB device is plugged in one port, even one of lower power > > like a > > > flash drive. (sometimes it only takes one, sometimes it takes two, SD > > card > > > power also seems to be an issue) > > > When I try to plug in the 2.5" HDD, it doesn't have enough power to > > spindle > > > at enough speed and sits there trying to start itself. > > > When plugging in an USB device or SD card after the 2.5" HDD is already > > > working, it suffers a loss of power and enters the restarting state. This > > is > > > true if the SD card is plugged in instead(with another USB device > > present), > > > which suggests me that the power is shared. > > > No other plugged devices seem to be rendered temporarily unaccessible due > > to > > > the power failure on the high power device. > > > Best regards, > > > Tiago > > > _______________________________________________ > > > Devel mailing list > > > [email protected] > > > http://lists.laptop.org/listinfo/devel > > > > > > > I see a similar issue with a Lacie drive on my Dell desktop. This > > drive actually comes with a cable that has two USB cables to draw > > power from two ports. With two ports, the platter spins without any > > problem. With one port, the disk clicks on the Dell. > > > > On a XO-1 G1G1, XO-1.5 B2 and XO-1.5 C2 I am able to power the same > > drive via one port only both with a SD card and without a SD card. The > > issue may very well be the USB drive power draw. I am using a LACIE > > Design by FA Porsche http://bit.ly/9HD5uI > > > > This will be important for XS-on-XO scenarios, where we would > > piggyback the /library partition onto an external drive. > > > > cheers, > > Sameer > > > > -- > > Dr. Sameer Verma, Ph.D. > > Associate Professor, Information Systems > > Director, Campus Business Solutions > > San Francisco State University > > http://verma.sfsu.edu/ > > http://cbs.sfsu.edu/ > > http://is.sfsu.edu/ > > > part 2 text/plain 129 > _______________________________________________ > Devel mailing list > [email protected] > http://lists.laptop.org/listinfo/devel =--------------------- paul fox, [email protected] _______________________________________________ Devel mailing list [email protected] http://lists.laptop.org/listinfo/devel
