Had a similar thing happen tonight. very faint burning smell...possibly form the PSU but not 100% sure.
I shut it off immediately, grounded myself, unplugged all drives, as I thought that perhaps a drive power cable was shorted, (has occurred to me previously in another rig) or perhaps some dust got somewhere it shouldn't have when I had cleaned out dust buildup from the inside of my PSU. Thing is that I had it running afterwards for a short time and it was fine. then I tried again after dinner and, burning smell. Runs fine now.
Other question. need info. I do have another PSU but the voltages are off.
my current PSU is a Dainty A300 ATX with voltages of +3.3v, +5v, +12v, -12v, -5v and +5vsb
the other PSU I have is a Orion HP400D with voltages of +3.3v, +5v, +12v1, +12v2, -12v and +5sb.
I'd liek to swap for the other PSU but the voltages don't match up and I was told by one shop that was no issue, and another not to do the swap as I could fry the pc. Help?