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Thread ID: 59081	2005-06-21 04:18:00	USB flash drive shuts down PC on connection	Eorr (2788)	Press F1

Post ID	Timestamp	Content	User
365736	2005-06-21 04:18:00	OK, haven't had any luck searching for this problem. Question is, has anyone got an idea what would cause my PC to shut down when I plug in a flash disk? And/or any ideas how to eliminate it? Specs: Windows XP SP2 home edition Athlon Barton CPU 1GB Ram MSI KT6 mobo SATA RAID disk drives The flash drive is a cheap one just bought called a 'Rundisk' 512MB model connected to a rear port of the PC (USB2) with the supplied cable. Other USB devices include hub attached to base of monitor which has a printer connected, thats all. This shouldn't have any bearing cause this happens before windows starts up also. Problem scenario: this has occured only three times since I bought it - plug it in every day for the last month or so. Happened when Windows had been operating for some hours - with apps open. As soon as the USB drive hit the cable plug, bang - total shut down - power lost completely, except monitor of course - had to switch off at wall and on again to reboot. The other occasion was when I plugged it in while booting - it was at startup procedure, windows not loading yet, and again, as soon as the disk hit the cable plug, shutdown. The only other time was also at boot time when I plugged it in and it wouldn't find any disk drives until I reset at the wall and rebooted. Otherwise this ram/flash disk operates very well, copying large files, filling disk, deleting, running apps from it, whatever - never a problem, except as above. Any ideas anyone?	Eorr (2788)
365737	2005-06-21 05:08:00	Dodgy power supply. The flash drive will draw power from the PC as it doesn't have its own supply. So - try another PSU.	pctek (84)
365738	2005-06-21 05:50:00	The maximum that the USB drive can use from USB port is only 2.5 watts though, and thats far less than the variations caused by other devices operating normally. One would expect to see shutdowns at other times not related to the USB drive if it was the power supply. Its possible, but I would suspect something else such as an intermittent fault (short circuit) in the flash drive first (although even that would not be expected to shut down the PC, but more likely disable the USB port)	godfather (25)
365739	2005-06-21 09:17:00	Try another USB device on the USB ports you are using. If it still occurs then it eliminates the flash drive as the problem. 2.5watts is not much true, but I'd check it out anyway.	pctek (84)
365740	2005-06-21 11:17:00	Go to www.rundisk.co.kr where you may find help in the user manual. I had a rundisk 128 MB which failed anhd was replaced without question.	TEEBEE (563)
365741	2005-06-21 22:42:00	Try another USB device on the USB ports you are using. If it still occurs then it eliminates the flash drive as the problem. 2.5watts is not much true, but I'd check it out anyway. OK, good point. I have previously been using another USB ram disk for many years without this ever happening - so I guess, even though it is 64MB and the new one is much bigger, which shouldn't make any difference in power draw-off etc. - that it has to be the USB drive shorting or something. Only happens about 3 in a hundred times though. Also, I have replaced the PSU less than a year ago simply to have a higher quality PSU and it hasn't given any other indication of a problem since then. Can't see how the PSU could be the problem if this happens while the machine is booting. Maybe the mobo though? So has nobody ever heard of this happening before? I can't find anything like this through google. Makes me feel kind of special. Great (not).	Eorr (2788)
365742	2005-06-21 22:57:00	Well, is the drive still under warranty? Seems you have narrowed it down to being the problem. I found a few forums with people with the smae problem. Suggestion were if using the front USB ports - they could be connected wrong. I doubt that, or its loaded the driver for it wrong - maybe, but XP just treats it as the same thing, so if the other one is OK, then not.	pctek (84)
365743	2005-06-21 23:11:00	Well, is the drive still under warranty? Seems you have narrowed it down to being the problem. I found a few forums with people with the smae problem. Suggestion were if using the front USB ports - they could be connected wrong. I doubt that, or its loaded the driver for it wrong - maybe, but XP just treats it as the same thing, so if the other one is OK, then not. Interesting, I couldn't find this in other forums - probably looking in the wrong place. Wasn't sure what to search for. Found stuff about USB problems and lock-ups etc, but not switch offs. You could post a link if you like? One point to add - I'm plugging into a USB port on-board the mobo (rear of PC), via a cable. I suppose the cable could be it. I'll bypass it for a while and see if it still happens. Another thing - this only ever happens at the time of initial connection. Once it's plugged in OK it operates flawlessly - quite fast too, compared to Sisoft records. Never any lock-ups or shut downs once it's in. Static possibility? Thanks for your help. Cheers.	Eorr (2788)
365744	2005-06-22 03:07:00	This is the sort of thing which "can't possibly happen" . :D At the worst, plugging something odd into a USB port should confuse the USB controller . The power available from a USB port is not going to bother the grunty 5V supply of any computer box . Even a dead short in the unit would just produce a puff of smoke (and nothing that drastic is happening) . Those RunDisk units are very cheaply made (the USB connector is just tracks on the PCB :eek: ) but the one I've seen does work . Could it be that movement of the USB "extension cord" at the back is disturbing a power cable or switch?	Graham L (2)
365745	2005-06-22 03:24:00	This is the sort of thing which "can't possibly happen" . :D At the worst, plugging something odd into a USB port should confuse the USB controller . The power available from a USB port is not going to bother the grunty 5V supply of any computer box . Even a dead short in the unit would just produce a puff of smoke (and nothing that drastic is happening) . Those RunDisk units are very cheaply made (the USB connector is just tracks on the PCB :eek: ) but the one I've seen does work . Could it be that movement of the USB "extension cord" at the back is disturbing a power cable or switch? This is very interesting . Shouldn't be happening, I agree . But no power cable disturbance is apparent . Also, it is very much a case of power loss the instant the metal plugs come in contact - very succinct . I am wondering if this could be static electrical related - that would explain the unexplainable quite nicely - hard to dispute I suppose . I still believe I've seen a computer shut off the instant someone touched a device connected to a serial port, but can't prove it was static related of course . But it never happened twice, and we were noticing static charges about the place then - you know, carpet/door knob stuff . But could static store in a USB drive, and could this power off a PC through the port - I still can't see how that could be, even . I'll keep using it direct into another port and post updates in future if I learn anything more, just in case someones interested . :confused:	Eorr (2788)
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