Turned it off this morning and wont turn back on again this afternoon. It's like I unplugged it from the wall – no sound of fans/harddrive, no lights.

Tested with a different fuse/kettle cable and wall socket. All fine.

It it most likely that the power supply is dead? Or could a motherboard or cpu fault have the symptoms?

Thanks in advance

I asked the same question last week, do a search. Anyway general answer was probably the psu knackered. Bought one for about £20 delivered. 10 minute job to change it and all working now.

Probably the psu, but I have had a motherboard pack up on me, so it's not guaranteed. If the cpu had dies you should still get activity, so I doubt it's that.

PSU i would imagine.

PSU should still try to fire up if it's anything passed the PSU.

The power supply is controlled by the motherboard so if that is dead the psu won't necessarily start when you press the power button.
In summary it is likely the psu but could indeed be the mobo

Yep. They could cause it but it is msost likely the PSU. Rob, borrow or buy a new PSU and if that doesn't fix it you're better off buying a new base unit.

Thanks for all the replys

Do PSU's have a form factor? I am running a mATX mobo in a mini tower like a older version of this
http://www.ebuyer.com/product/130946
So will any PSU fit?

One thing I've learn't. Must vacuum the case more often.

This might sound a bit stupid but you haven't accidentally switched the main power switch on the back off!

I bought my psu from here http://www.microdirect.co.uk/Home/

Thanks fs. I read your thread last month and much help on there.

nob – have checked power switch. Still no good.