Temperamental USB ports

[mathare]

I bought myself a USB memory stick for christmas. It works fine on my PC at work (Win2k) but is a bit temperamental on my home PC (XP, service pack 2).

Sometimes (well, quite often actually) it reads the drive but when I try to access anything on it (copy to/from the memory stick or open a file on it) the light on the memory stick goes out and the data access fails. Normally a reboot sorts it out.

Is it likely that the problem is my motherboard or what? I have not noticed any other problems with these ports but then I don't use them that often.

[TheOldhamWhisper]

If there is a trade name on the drive, try finding the site to see if there is a driver for XP or something. Some of the older flash drives seem to have this problem on XP but are fine on W2k.

[Win2Win]

Shouldn't really be a problem on XP, as it doesn't need a driver. Is it USB 1 or 2, as this may cause a clash it's not happy with.

I've just started using these and they are excellent. If the laptop explodes, or something, I have everything I need on the stick to continue.

[GlosRFC]

One of the problems with the USB spec is that it's been implemented slightly differently by motherboard manufacturers. Some even have different standards for USB1.0, 1.1 and 2.0. Your first port of call should be to check the website of your motherboard manufacturer to see if they have an update.

Add in the fact that, despite the propaganda, USB devices actually don't like sharing IRQs which can make hotbooting something as vital as a drive somewhat problematical. Oh, and different file systems on the storage device/PCs e.g. FAT, FAT32, NTFS, and the weird proprietary file systems used by the manufacturers. And not forgetting that XP wasn't designed to support USB (MS actually wanted to provide native Firewire support instead) and it's little wonder that some memory sticks are notoriously unreliable.

You can try installing a driver although XP "should" automatically detect these devices so most manufacturers will probably only have a 98SE driver on their websites. Most likely is that you may need to reinstall the USB driver from your XP disk. Either way, be sure that the device is not plugged until prompted to do so after installing the driver - XP has hiccups over this.

SP2 also introduced a new security option to disable memory sticks. I'm not sure if this is enabled by default but it might be worth checking your registry in HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control \StorageDevicePolicies - look to see if you have an entry called WriteProtect. If not, then that's not the problem but if you do, check if the value is a 1 or a 0. 1 prevents access to the drive while 0 allows it.

Do you have other USB devices attached? If not, XP sometimes powers down the USB controller and it then sometimes forgets to "wake up" and recognise the device. This doesn't sound like your problem though as you say it is recognised.

When you plug it in, is it shown in Device Manager? Sometimes just plugging it into a new USB socket triggers XP into re-recognising the device and it will reinstall the drivers automatically.

Microsoft gives some details on removing & reinstalling USB controllers that could be a last resort http://support.microsoft.com/default.aspx?scid=kb;EN-US;310575

Hope this all helps.

[GlosRFC]

One quick question. When you insert the device does XP give you any indication of the drive letter that's been assigned? Sometimes the device is recognised properly but XP has problems assigning a drive letter (particularly if you have one of those multi-memory card readers attached) and this can cause problems reading/writing to the device. To get round this:

1. Click the Start button, right-click My Computer, and then left-click Manage.
2. Click Disk Management in the left column.
3. In Disk Management, right-click the disk labelled Removable, and left-click Change Drive Letter and Paths.
4. The Change Drive Letter and Paths box will open. Click the Change button and change the drive letter to one that is not being used, e.g. M or N
5. Click OK and Yes to the warning "Changing the driver letter of a volume might cause programs to no longer run"

Exit from Disk Management and then fire up My Computer to see if your device is now visible.

[mathare]

Right. I think I have got all that.

It's a Super Talent Flasm SM_USB20 drive so USB2.0. Can't remember what the MOBO is, Asus or Abit I think.

When I plug it into my front USB ports I have a few problems, but it worked in the back ports the couple of times I tried it last night. Also other USB devices worked OK in the front ports but the testing I did was hardly extensive.

It gets a drive letter fine, it becomes J now. I have two HDDs, a floppy, DVD-RW and a multi-media card reader in so it takes the next available letter.

When I plug it in it is usually the only device in the front ports but my scanner and speakers are in the back ports.

The device is shown in Device Manager as far as I can remember, yep.

I may try reinstalling the USB controllers.

Oh, and the manufacturer's website has only Win98 drivers

[GlosRFC]

Seems like the device is working okay then. Could be a problem with the overall power supply across your USB ports. When you connected it into the back which device did you unplug and did you plug it back into one of the front ports and then tested the memory drive?

Conceptually it's possible to attach 127 USB devices to a PC but, in practice, Flash drives and scanners tend to be the most power- and bandwidth-hungry so the 5 volts/bandwidth allocated across your USB ports might be a bit stretched. If that's the case, you can experiment with different combinations of devices attached until you find one that works for you. I suspect it might require unplugging of the scanner each time you want to use the memory drive.

[mathare]

Seems like the device is working okay then. Could be a problem with the overall power supply across your USB ports. When you connected it into the back which device did you unplug and did you plug it back into one of the front ports and then tested the memory drive?

Scanner was unplugged from the rear port. Didn't plug it in the front because it didn't reach without rearranging a lot of the stuff round my PC :(



Conceptually it's possible to attach 127 USB devices to a PC but, in practice, Flash drives and scanners tend to be the most power- and bandwidth-hungry so the 5 volts/bandwidth allocated across your USB ports might be a bit stretched. If that's the case, you can experiment with different combinations of devices attached until you find one that works for you. I suspect it might require unplugging of the scanner each time you want to use the memory drive.
Thanks, I will experiment and see what happens

[GlosRFC]

I appreciate it means humping stuff around but it would be interesting to know if the memory device still functioned in the back if the scanner was plugged into the front. Might also be worth checking if the scanner still functions too when it's been moved. I suspect one or other of them may start misfunctioning. If so, you'll have to resort to plugging in only the one device at a time or try the Bios upgrade.

Best of luck with it.