Troubleshooting weird hardware/software issue

I'm trying to fix my (somewhat technology illiterate) friend's computer.  They keyboard and mouse (both razer products) will work for about 30 seconds after booting into windows 7.  Then the backlighting will flicker and turn off/back on a few seconds later.  All input from the keyboard and mouse stops completely.  In safe mode they both work fine with no issues with the lighting or input.  My cheapo power supply tester said that one of the 12V rails? was not putting out any voltage.  Does this sound like a bad power supply? Driver issue?  The motherboard (i think the brand was Tseries) also has some red lights on it that look like they may be error indicators, but i have no manual.

Sorry for some of the typos and whatnot, just got a new keyboard and am not used to how heavy the keys are. MX cherry greens

does it do the same with a different mouse and keyboard?

try pluging the keyboard and mouse into different usb ports

different mouse/keyboards have the same problem.  There are only 2 usb 2.0 ports on the front, 2 on the i/o, and 2 3.0 on the i/o, all have the same problem.

does the motherboard have a ps/2 port it might be a driver issue seeing as they work in safe mode?

Don't have an adaptor or a ps/2 device.  It seems like it's a driver problem because it works in safe mode, but i've tried multiple generic usb keyboards and mice and they all do the same thing.  They just "power off" after 30 seconds or so.

maybe a failing motherboard or failing usb ports. could also have somthing todo with power supply like you were saying try a known good psu.

also look for identification marks on the motherboard.

Many 12V rails won't display actual 12V on most tester so no worries there. If they aren't already ensure that they devices are directly connected into the motherboard and not through an extension cable or daisy chained.

After that try booting into safe mode with networking and download new drivers from their website. After that delete your old drivers (control panel/ hardware/ device manager then keyboard/mouse from there) and install the new ones.

Do you have an extra PSU around to test the rail issue, or "borrow" one for the troubleshooting?

It was showing a reading of 0V and had the "failure" indicator.  Would a computer even work if a rail was totally shot?  They are not chained, plugged directly into the back i/o.  The keyboard and mouse were both using generic drivers instead of razer's drivers, but we tried multiple keyboard/mouse combos.  Even my usb drive doesn't work.  Would download new USB controller drivers help?  I feel like this is a hardware issue, just the fact that things work in safe mode has really thrown me off

try a different power supply and see what happens.

don't have an extra psu lying around im afraid :/  i think we are going to go with reinstalling windows for now.  the computer is so cheap that it just needs to survive until my friend has enough to build a new one.

take a good look in the power supply with a flash light and check for bad caps.

http://i422.photobucket.com/albums/pp306/terren-ART/IMAG1547.jpg <-- example also look on the motherboard for bad caps a bad capacitor is one that is leaking and or bulging.

this is probably irrelevant, but the problem ended up being an outlet issue