I've got a self built PC that's been RUNNING smoothly for 6 months,  Early december, after a move, sometimes on power up, and sometimes at random, the computer will emit a low, continuous buzz until it's rebooted.  sometimes this fixes the buzz, sometimes it doesn't.  The buzz seems to correspond to the HEATSINK fan (plugged into the motherboard) not getting power.  Is this something I can fix without an electronics engineering degree?  Is it the start of a bigger problem? And is there a way to disable the buzz?

Motherboard - Gigabyte K8NE
Processor - AMD 3400+
1. Check to see if there is a insect in the fan.
2. Remove the fan, clean it using a mild solvent like rubbing alchohol. Let it dry well, put it back and see. :-?
3. get a new fan.  
I've replaced the fan with an Antech 80mm fan, and disabled the fan failure alarm.  The fan works fine when it's plugged into the power supply, but the 3 pin connector on the motherboard doesn't seem to work, or works intermittently.Sounds like there's a dodgy connection on the motherboard.any reason something like that would work fine for half a year before crapping out?Could have been a power SURGE from your outlet or a failing power supply, could have been static electricity discharge, could have been normal everyday hardware failure, could have been leeking or bad motherboard capicitors.  (Here is a link with lots of pictures showing how capicitors can sometimes go bad and what to look for. http://www.burtonsys.com/bad_BP6/).

Sometimes hardware just fails, and it usually happens without warning.  Which is why many of us try to instill in our clients the need for regular data backups.  Now 6 months is definately a premature failure and you should maybe check your warranty for coverage.You should likely ALSO check all your computer cables, especially the CPU fan one, for frayed wires or scorch marks, and check your motherboard for scorching.If the MBoard is 6 mos. old i would be taking advantage of the warranty just to be on the safe side...

patio.  8-)