Computer problem!

[Lily]

So I've got a small but rather annoying problem with our computer, it has a problem with it's power switch, it started a month ago or so and I have no idea how to fix it.

So, the computer and all of it's components is connected to the wall socket through an extension socket with and on/off button.
In the morning we turn the power on on the extension socket and then we press the power switch on the computer - it used to boot directly before - but now the lights turn on on the tower and then nothing. We hold in the power switch to turn the lights off and then we try again., it usually takes about three times before the fans start and the computer boots.

We've got no other problems with the computer. Any ideas on what the problem can be?

[Zilla]

Are you shutting the computer down or using the wall switch to shut it down? I get the impression that it is being shut down properly, but if it isn't, that could make things wonky for lack of a better word.

[Lily]

Zilla - We're shutting the down the computer properly. To me it seems like it takes some time for the electricity to reach the computer switch. Wonky cables perhaps? The thing is I have no idea what to look for when I open the tower!

[CharlieChomper]

There are quite a few things that may be causing that type of situation. I actually went through similar to this with one of my own systems...

How old is this computer?

Have you added any new devices to the computer, recently? Particularly anything which may in some way draw power from the computer or is hooked up directly to the power supply?

Does the computer make any noises when this happens?

When you are able to get the computer to finally turn on, does it make any groaning sounds? The reason I ask is because temperatures (ie the room or location of the system either being too cold or else too hot) can sometimes affect a system in such a way as to cause that--but, it's not very common for that to be the result of something like that.

On a related note, when was the last time the fans (internal and external) were cleaned?

The easiest thing to try might be to see whether plugging it directly into the outlet has the same effect (on a related note, when you say extension socket, is it a "power strip" or is it more like an extension cord or cable? If it's a power strip, are there any other devices plugged into it and are any of them having problems?).

If the computer still behaves that way, it may point toward a possible hardware problem.

The next thing I'd recommend looking into would be your BIOS voltage readings.

On a related note, what manufacture/series is the motherboard and power supply?