Keyboard stops working, then restarts only when unplugged and plugged back in

Question

I'm a desktop support technician and I have run across a very strange issue.  I have a user who had an issue with his keyboard.  It would all of a sudden quit working out of the blue, right in the middle of typing something.  It would only start to work again once he unplugged it and plugged it back in, this would happen to him several times per day.  The first thing we did of course was plug it into a different usb port, that didn't make a difference, we tried them all.  Then we tried a different keyboard, didn't make a difference, tried yet another keyboard, same deal.  The next step was to replace the motherboard, did that, same problem.  Last but not least, we reinstalled windows XP on the machine, remarkably, no difference, same problem.  At this point the user was sick of dealing with this, so he went out and bought a new computer, a 760 SFF.  He bought the whole kit and kaboodle, pc, monitor, keyboard, mouse, the whole deal.  I set this up for him a couple days ago and was absolutely floored when he called me back and said that his keyboard was doing THE EXACT SAME THING!!!!!! HOW IS THIS POSSIBLE????  I'm baffled by this, the only common variables in this equasion are the operator and the wall outlet and power strip.  I'd really like to hear some peoples thoughts on this as I am at a complete loss on this one.

RoHe · Accepted Answer

Another thought...

Some times when the system has a lot of power-hungry USB devices connected (eg, printers, scanners, external drives, etc), the system will turn something off to avoid a USB overload. In this case, power-hungry devices should be connected through rear USB ports which typically provide more power than the front ports.

And/or you may need an externally powered USB hub with its own power brick. Connect the hub to a rear USB port, plug its power supply into the wall and then connect the power hungry devices through the hub.

Ron

gr.tsimmons · Answer

Nope, this is actually a rediculously simple setup.  Wired USB mouse, wired USB keyboard, no unusualy op proprietory software what so ever.

DCX4EVER · Answer

Is this person using a wireless KB and mouse utilizing the usb interface? You have ruled out everything except the user and his enviornment. Is the operator installing some unknown software that is comon to both systems?

Ruggerducky · Answer

Wow, ok, apparently Dell deleted my previous post, so I'll repost this:

I am having a very similar problem with an Optiplex 960. We tried 4 brand-new keyboards out of box, all work fine in BIOS, DOS boot, everything until you get to ANY flavor of WinXP (HD, boot CD, or external boot drive). Flashed BIOS, F-disk'd the drive, reinstalled Win fresh, tried everything you can possibly imagine. No luck. Then took it upstairs and plugged it in, worked fine. What the HECK? Went back to the office in question, plugged back in, no joy. Brought down the keyboard from upstairs, works. The ONLY difference is that the keyboard that works has an RF filter on the cable. All are Dell keyboards.

So I guess try a keyboard with an RF filter on it. If it works for you, please, please let me know, because these gremlins are making me crazy!! I've been pulling out all the networking tools trying to find some random signal that seems to be interfering.

Ruggerducky · Answer

Did that already (power management). Also have disconnected everything except keyboard and mouse. If I need an externally powered USB hub for a wired keyboard, then I won't ever buy another Dell for my departments, that's just twisted. Seriously. This computer has been completely rebuilt, and the ONLY thing that allows the keyboard to work in this case is the filtering on the cable. All non-filtered keyboards fail to work.

RoHe · Answer

Open device manager and expand the list under USB. Double-click each USB root hub and click its Power Management tab. Uncheck the box "Allow PC to turn off this device...". Repeat for all root hubs and reboot.

Does that solve it?

Ron

gr.tsimmons · Answer

Hey I wanted to thank you for your help and let you know that yes, this did work.  We did not have any keyboards with RF filters on hand but we did have a wireless desktop setup, which of course has the built in filters, it's been two weeks and the problem has not occured anymore, seems to have done the trick, thanks a lot.

th3boss440 · Answer

Another common variable could be installed software?

dyinins · Answer

In this case, power-hungry devices should be connected through rear USB ports which typically provide more power than the front ports.

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Keyboard stops working, then restarts only when unplugged and plugged back in

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