USB Ports Not Working

November 9, 2009 at 19:28:26
Specs: Windows XP
Hi everyone! I need some help figuring out
what's going on with USB ports not working. I
hope I provide enough information.

OK, so the computer is a Dell XPS, couple
years old. The USB ports are not working.
Bios does not recognize that a keyboard is
plugged in - unable to enter Bios. Laser mice
do not light up when plugged in.

I added a USB PCI card. This too does not
work. Still no light on laser mouse. I'm pretty

I tested the PSU. -5 tests bad. I know that
USB supplies 5v - so I order a replacement
Dell PSU. The -5 on the new PSU also tests
bad. USB ports still do not work with the new

I've ran into this same scenario before and am
trying to learn what's going on. My view now
is that the motherboard could be bad. But
before buying a new motherboard, I am asking
for some help/insight. Is it common for power
supplies to have -5 test bad? Is this an actual
problem with the psu or is it the tester
misreading? Why would the PCI USB card
not work as well?

Thanks for any help!

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November 9, 2009 at 19:47:45
I recall someone posting in the past that the -5V is only used by motherboards with ISA slots. Those are virtually non-existent in modern motherboards so it is unlikely the powersupply is your problem.

I'm inclined to look for missing chipset drivers as the reason your USB ports aren't working. Check in devicemanager to see if any USB controllers are listed and if any yellow ?s are evident.

Goin' Fishin' (Some day)

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November 9, 2009 at 19:54:07
Thanks for the response. The keyboard does not work during
POST, so drivers would be a no-go. This is a USB only
motherboard (no PS/2 ports).

Also, I've pulled the battery to reset BIOS, just in case they got

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