Okay, recently (I don't know it this has a connection with the past power cut), it seems that the power supply of my CPU is making some really bad noise. However, it only starts a few seconds after having switched on my computer.

What I did up to now was to shut down as soon as possible, wait for some time and switch on again. It would then most of the time boot without the power supply making the horrible noise.

I don't know how to describe well this noise... it's maybe due to the fan. It a little like something was touching the fan and doing some 'motor like' noise. That could also not be it, but I'm just trying to put as much detail as I can. We replaced this power supply sometime in July last year because the other failed and had to be changed (it was getting old). I don't recall the previous one having this problem.

It started for the first time in November but since it occurred once or twice, I didn't bother much about it. Now it's like every time I switch my computer on. I have to shut down and reboot. Pressing the restart button on the CPU doesn't remove the sound.

Any idea of what might be happening? Or someone who had similar problem and has experience with it?

Thanks!

Your initial guess is as good as any. Something may be touching the fan blades.

Disconnect power from the case and open the side. You know the cables are safe to "adjust", so move them around so they aren't near the PSU fan nor the CPU fan, and any other little fan you might have in there. Be thorough.

Leave the case door off and boot the computer. If the noise returns you'll be able to get a much better idea of exactly where the sound is coming from with the door off.

If it's the PSU fan, replace the PSU. They're very inexpensive, but buy a good one.

Well, I did open the CPU and I'm almost certain it has something to do with the PSU. What I'm not sure is whether only the fan can make this noise or something else.

And with all the cables inside, I'm afraid I can't plug in the right plugs so that I can start the computer again :o

This probably means I'll have to replace the PSU... dang... I'll need to find sometime I'm not busy. Thank you!

This current PSU has been used for such a little time compared to the previous one :(

Perhaps a warranty claim then?

I'm not sure... I'll ask the person who changed the PSU for us. The thing is, it'll be some time before I can meet him. Anyway thank you again! :)

This happened again today... :(

Grrr..

http://www.smpstroubleshooting.com/2011/12/smps-troubleshooting.html

Replace with a cheap Power Supply, and you are asking for trouble. A decent Power Supply doesn't have to cost an arm, and a leg, but you need to research the unit, and see what the reviews are.

Low quality Power Supplies have;
1) Too small a gauge of wiring
2) Low quality capacitors. (Usually Radial Aluminum Electrolytic Capacitors)
3) Low quality Rectifier Bridge
4) Low quality power MOSFET's.

You can almost guarantee it is a good Power Supply, just by the weight. Light power supply's are low quality.

A decent, reliable Power Supply cost, averages around $35 to $50.
(Unless you feel like replacing them a lot)

Also choose a Power Supply with at least 10 percent more power, than is needed. Helps the Power Supply last longer.

Plus ALWAYS keep the inside of the computer, AND the Power Supply, clean.
(FOLLOW Anti-Static Precautions BEFORE opening the computer, AND during cleaning )

Regards,
joecoolvette