CPU is ticking like a clock

[Bird of the South]

Well could the hard disk be on the way out? Does anyone have any suggestions. I am thinking of taking the casing off and checking for loose wires and giving it a dusting over but am I wasting my time??

[grumpy]

Unless you are sure of what you are doing I would leave the case where it is, chance of electric shock. If you are worried about dust holding a vacuum cleaner against the fan outlet would probably help to get rid of any dust. The

first thing I would do is make sure that the hard disk is backed up in case of it being about to fail. At least that way your data is preserved.

[AntonyM]

You need to work out where the ticking is coming from - it could be a fan, but it would usually indicate a hard drive on its way out, so back up all important data first (whilst it is still working).

Then, with the power off and disconnected, it is fine to open the case and give everything a good clean. It could possibly be something touching against a fan, or it could be an overheating issue causing the hard drive to work hard. Use a soft brush and vacuum all the dust/fluff out of the case and any fans/heat sinks you can see. Be careful not to dislodge any wires, so go gently.

[PeteW1959]

I agree with Antony; you are perfectly safe to open the case as long as the power is disconnected.

Even if you forget to disconnect it you are still safe as any dangerous voltages are safely encased in the power supply; the computer itself runs on 5 volt and 12 volt supplies.

Another cause of ticking is a power supply on its way out, but either way it should be relatively inexpensive to fix. Hard drives and power supplies are quite cheap components, but I would suggest taking it to a computer shop as they can copy everything from your old hard drive to a new one.

DON'T GO TO PCWORLD. They will charge you the earth if they do fix it, but they are more likely to convince you to buy a whole new PC. Local independent computer shops (preferabley recommended by someone who has used them before) are your best bet.

[Bird of the South]

Thank you for your replies especially the advice about local computer shops vs PC World. All my data is backed up on an external hard drive. I gave the casing a small thump with my fist, and guess what; the ticking has stopped. I think I will give it a clean though as after 3+ years use it is bound to be dusty.

[PeteW1959]

As a thump stopped it ticking, it is almost certainly something that one of the fans is catching on. Give it a clean out, and have a good look for cables that are near fans.

In most PCs, there is a fan on the processor (it will be a big one right in the middle of the main board) and a fan in the power supply (don't go near this one DANGEROUS VOLTAGES ARE PRESENT, even after it has been switched off) but cables are extremely unlikely to be catching there.

There may also be a smaller fan on a graphics card (on a card that is on its edge on the main board) and one or maybe 2 in the front or side of the case.

It may even be that the bearings in one of the fans are failing. These are very cheap items and again your local computer shop should be able to help you.

[Bird of the South]

Thank you. Ref the dangerous voltage that is present after switch off, how long does it have to be switched off before it is safe to clean around that area?

[PeteW1959]

30 minutes is required to allow everything to fully discharge. However the fans in the power supply are behind grilles and there is no way to reach the dangerous bits without removing screws. Just don't poke anything into any holes!

[Bird of the South]

Thank you. I like your Avatar.