Strange behaviour during PC repair

A client asked if I could look at his home PC which I've done work on in the past, including upgrading the drives, replacing ram and reinstalling XP.

He said the system had just suddenly shut down whilst he was using it, and when restarted it only stayed running for another 10 minutes before it then shut down and wouldn't start up again.

I plugged it in and it powered up to the desktop without a problem so I thought it might have just been one of those odd things that sometimes happens. But I then noticed the back of the case was getting very hot so opened it up to discover the graphics card fan wasn't spinning due to dust build up.

I cleaned the dust from the case and graphics card fan and the fan then started spinning again but was definitely on its last legs due to that horrible squeaking noise you get as they are failing.

Then the system shut down as he described and wouldn't power up again. I unplugged the system and had a good look inside, but everything seems to be plugged in firmly. I connected the power again and without pressing the soft power button on the front of the case the cpu and graphics card fans started spinning which is a bit odd. And the cases front power led was flickering instead of being constant.

I ended up trying a different graphics card but that wouldn't power on anything. I did get the system to sort of power up once with the keyboard num lock light coming on but nothing else, and the monitor didn't get a signal.

So now I'm thinking the PSU is faulty along with the graphics card. What do you all think?
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Forgot to add something else.

I thought I would fully disassemble and rebuild this PC so I know everything is connected and correctly installed before I do go and get another PSU. So I thought I would remount the CPU as the heatsink and fan were quite clogged up with dust. So I unclipped the heatink and tried to take it off but it came out with the CPU firmly stuck to the base of the heatsink.

On looking at it closely it actually looks like the original installer has stuck the CPU using some sort of glue.

Not sure how I'm going to get this off the heatsink! It is a P4 though so does have the big metal heatspreader on the CPU. Would have been worse had it been the older AMDs that didn't have a heatspreader fitted.

So now I have to find a way to get the CPU off the heatsink. Ideas?

I am going to try some 100% alcohol to see if I can dissolve the stuff holding it on. If not I will have to try and pry it off somehow.

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Think you can cut through the glue using one of those knives with long thin razor-sharp blades (don't know what they're called exactly, kinda like those Stanley-knives but much longer blade)? That'd still leave residual glue on the CPU though, but it'd be easier to get off with the heatsink gone.

This definitely sounds like a toasted PSU to me, but there's always the chance that it's the motherboard itself that's acting up.
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Could you maybe try something like "Goo Gone" to get rid of the glue?
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Possibly a little heat (like a hairdryer or something) while trying to prise it off. May or may not help, depends on the type of glue they have used.
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Hmm, but the glue would have been heated up and cooled down numerous times, so it would require a lot of heat to melt that hard glue. Wouldnt that damage the components? It sounds like you'll have to dissolve it....my best choice would be hydrochloric acid. That dissolves everything!

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Yeah, including the CPU I would think!

When I did a search lots of other people have had similar CPU stuck on Heatsink problems and some did mention Goo Gone. I've not heard of it and wonder if it is for sale in the UK.

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Here are some Goo Gone products, I just looked what it was on the net, as I myself haven't heard of it either. Seems like another Cilit Bang (or what's that called?).
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How old is the PC? Would it be worth re-evaluation rather than troubleshooting? Or even time saved on trying to sort it out?

I mean if you are unsure that it is definitely the PSU....it could be a voltage issue with the mobo...the heatsink stuck to the CPU issue on top, how much time do you want to spend investigating? Time is your monetary loss as well as a pc repairer dont forget....

Depending on the clients computing needs, it may work out more cost effective with less labour intensive repairs to actually get another motherboard (with onboard graphics unless he is a gamer), CPU and PSU if diagnosis is proving troublesome, providing the exisiting RAM is compatible and hard disk, drives etc are ok.
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