On Sat, Apr 24, 2010 at 12:04 PM, Tiago Marques <[email protected]> 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. > Best regards, > Tiago
What brand/model of drive are you using? Sameer > 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/ > > _______________________________________________ Devel mailing list [email protected] http://lists.laptop.org/listinfo/devel
