Yes it is just as simple as unplugging the old one and replacing, But before you going spend $90-$140 dollars on a new power supply how long have you had this build for, And please post the PC specs.
erm, its maybe 1/2 years old?
q6600 2.4 ghz
asus p5n32-e sli+ mobo (which might be dodgy too cos i stupidly tried overclocking using ntune)
640mb 8800gts (ditto as above)
i mean its a fairly decent spec pc which i use mostly for gaming, although at the moment its slightly out of commission.
can't remember what wattage my current psu is/was. could this have happened because it wasn't powerful enough?
also, if i'm looking to replace the mobo, is there anything decent for a reasonable amount of money, say 80-100 quid that is compatible with both my current cpu and maybe the i-series cpu's, or do they use completely different sockets?
When overclocked the Q6600 is still a nice CPU. I don't think that anything you could upgrade would give you enough performance increase to make it worth the expense.
PSU died because
1. Inadequate capacity,
2. Inadequate quality, or
3. Just a random failure.
If you had posted PSU specifications, we could make an educated guess.
Overclocking: This is why, for CPU's, we all say, "Learn to use the BIOS". For GPU's, you have no choice but to use a Windows utilty. I do not like overclocking video cards. They tend to run hot enough anyway.
The paperclip trick is not really that useful. If the fan doesn't spin up, it's dead - or there's not quite enough load on it. If it does spin up, all you really know is that it produced enough power somewhere around 12 volts to run a fan. Now, if you have a DMM or a PSU tester, it's a little better. You can check all the voltages, but you still do not know if it will support the electrical load of a computer.