I recently gave my PC a clean-out as I had not done so for quite a while. After cleaning it out I reconnnected everything and switched it back on.
About 3 to 5 seconds after switching it on it started making a loud revving noise. On inspection it appeared to be coming directly from the PSU. I grabbed a can of compressed air and gave the PSU a good clean through, after a while the noise disappeared, and I was able to run the unit for a good 4 hours with no such noise coming from the back.
This morning I switched it on and the noise was back, despite further cleaning I could not get rid of the noise so I am not using it at the moment for fear I could damage something else ie: HDD's etc.
I've read that this problem can be caused by a faulty fan, and that I would need the PSU replacing if this was the case. I also today found a small piece of thin metal that curls round, very much like a small paper-clip, This could be off one of the fans or something else intenal.
Could anyone offer any help? I've got some rather important work to get on with on there so it is killing me not been able to use it , It also seems weird that I managed to stop the noise for a while and then it came back.
Anyone have any ideas/advice?