My Mac Pro stops recognizing certain USB devices

[blueshogun96]

Ever since last night, I discovered that my Mac Pro (1,1) has suddenly decided to stop recognizing certain USB devices that I commonly use. Some things work (i.e. mouse, iPhone when plugged in), but others don't (Apple USB keyboard, USB thumb drives). I tried plugging my keyboard into my Macbook Pro, and it works fine. Same goes for my USB drives. I also tried changing the USB ports to use, still nothing. Tried restarting, STILL nothing! My mouse works no matter what port I use, but the computer is a brick if I can't log in and start typing.

This is ridiculous. Has anyone else had this problem? I'd give you the model number of my keyboard if that helps, but I'm at work now, so that will have to wait. Any ideas? Thanks.

Shogun.

 

[crjackson2134]

Download a Linux LiveCD such as Ubuntu, and boot from CD. Select TRY Ubuntu (or whatever version of Linux you download). Then try to use the USB devices again from the Linux desktop. If they work, you have an OS X problem. If they don't work, you have a hardware problem. They're both easily fixed, but you need to narrow down the problem.

 

[blueshogun96]

I dunno what happened, but it decided to work again. Before leaving for work, I turned it off, unplugged the keyboard and USB devices. When I came back, I unplugged the machine for a bit, then plugged it back in. Now everything works again. Gee, that's strange...

I would have tried the Linux thing, but since I'm not using an EFI compatible video card (it's a PC card), I can't see the boot menu.

Shogun.

 

[crjackson2134]

By unplugging / re plugging you did an SMC reset which seems to have cleared the issue.

You don't need the boot menu to boot an optical drive. Just press and hold the C key when booting.

Startup Options

 

[blueshogun96]

Okay, sorry to bump an old thread, but this issue happens much more frequently now. Sometimes it can happen 2 days later. Tbh, I have no idea what is causing this. Unplugging the Mac Pro overnight solves it temporarily. This really sucks because it tends to happen when I need to use it most.

I tried resetting the SMC by unplugging it, holding the power button for 15 seconds, then plugging it in and starting it up 5 seconds later. Could it be PRAM or NVRAM related?

Shogun.