Can a USB port be nudged?

Hi,

I have 4 USB devices plugged in at any one time to my XP SP2 comp. I only have 4 USB 1.1 ports in total, so I have to swap out the rarely used items. However, I keep my printer and my scanner plugged in at all times. The printer works fine, it is almost never lost. If it is lost, I just have to turn it off and back on again, but that happens no more than once every 3 months or so. The scanner is a whole different problem. It gets lost regularly, and I have to reach behind it to unplug and replug the USB cable (it has no on-off switch). As soon as I do that, it is found again and works flawlessly.

I found an article in PCWorld about this exact problem. The author said the best I could do was try to move the USB connections around to find the ones which stay connected (some ports have more power than others), reboot, or plug and unplug the connection to let it be re-established (exactly what I was doing).

Does anyone know of a USB nudger, something I can use under XP which will reset the USB ports without a reboot? It would be very handy if the scanner didn't respond, I could just launch a little app to nudge it (as if I were disconnecting the USB cable) instead of having to reach behind and pull the cable. I have tried to do this via Device Manager's "Scan for Hardware Changes ", but no luck. Any other ideas?

Thanks,
R.

 

i might take a crack at installing an external (powered) usb hub. eg - go get a USB hub that has a power adapter since many devices require a/c powered USB to work.

 

All my devices are USB 1.x

It may come down to a PCI USB 2.0 card, but I doubt it will be any better. This is a generic USB problem (according to PCWorld). What I was looking for was just some way of having XP reconnect to USB devices without me having to manually disconnect/reconnect them. My next computer will definitely have USB 2.0, but in the meantime, since I have no USB 2.0 devices, I may as well stick with USB 1.1 and hope someone can find an answer to this problem.

In the meantime, I'll grab a powered USB hub off of eBay. They are selling for nothing since no one wants USB 1.1 any longer. Hmmm, I don't have a USB header on my mobo now that I think about it, that was the reason I didn't buy a USB hub way back when......

R.

 

Hi ... Try this go to devise manager and locate the devises you are talking about , In your case it would be the scanner , expand the usb section in the devise manager area , locate your scanner , right click on it and then select uninstall , Once that is done go to the top area of devise manager and you will notice a tab name " Action " click on that and then click " Scan for hardware changes " This will reload the scanner again without having to reboot ... See if that helps

 

Rooster6975,

Go to 'DeviceManager', then to 'Universal Serial Bus Controllers', then right-click 'USB root hub', select 'Properties', then the 'PowerManagement' tab. Make sure 'Allow the computer to turn off this device to save power' is not selected. HTH

B

 

All these may or may not work. I have been seeing this type of problem for last so many years and have yet to find out any permanent solution for this. Best to get a hub or juggle around the devices till you find the correct combination which works.

 

a good point ... particularly on a scanner or such since it's inactive most of the time.

and i'd check the MB maker for FW/bios updates maybe ... could be helpful if it's usb onboard.

 

Ooooh, power management for USB root hub....

That sounds mighty promising! I have 2 root hubs listed, (the second comes from my printer). Both of them had the option "Allow the computer to turn off this device to save power" selected. I have deselected it on both.

To Snooker, yep, tried that before, it didn't help. The device is not found until I physically unplug it and plug it back in again.

Thanks for the suggestions, we'll see if the USB power management option makes the scanner stick around.

R.

 

****, still losing it.

Hi,

Thanks for the suggestions. The scanner is still being lost even with the "Allow the computer to turn off this device to save power" turned off. My next best option seems to be to acquire a USB2 PCI controller card. Does anyone know if the USB 2.0 specification actually calls for more power to be sent over the line than it did with USB 1.1? When I google that, I seem to get a lot of conflicting advice....

Thanks,
R.

 

rooster,

I couldn't locate that 'precise' info. If you open device mgr and bring up the USB Root Hub properties, is there a 'Power' tab that tells how much power each USB port receives? My USB 2.0 properties state 500mA per port, then it lists the actual power each individual device is using. These are the same for my internal ports as well as an external powered hub. I would guess that this is more than likely a 'standard' and a PCI card would be the same. HTH

B

 

**** man, you are good.

Yes, that tab (which I have never noticed before) does in fact state Total Power Available : 500 mA per port. My scanner (I pulled the USB connector earlier today and reset), is listed as drawing a whopping 2 mA. It's the Epson Perfection 1250 and it responded when I launched the scanning app. The next time I lose it, I will check the USB hub power settings and I am willing to bet it won't be there.

However, there is a "Refresh" button on that dialog box which I can click to see if it finds the scanner the next time it gets lost. This may be the nudger I was looking for......

Thanks,
R.