dead pc?

[id_wright]

ok, so i was using my computer earlier this afternoon and it suddenly switched off. i left the room, then came back in a couple of minutes later and noticed a burning smell. i hadn't noticed this before, but the power led was still lit, so i switched the computer off and unplugged it. the back of the power supply was extremely hot, so i left the whole thing alone for a few hours to cool off. i tried booting it up again later, but nothing happened apart from the power led coming on.
so... i'm guessing something fried. any way of finding out what so i can hopefully just replace that part? are my hard disks still likely to be functioning, or will i have lost all of my stuff? ditto for memory, graphics card, sound card, cd and dvd drives etc?
many thanks

AMD Athlon XP 2400+
Asrock K7VM2
2x256mb PC2100
HIS IceQ 9800 Pro
2x80Gb WD hard disks

 

[id_wright]

ok, thanks for the replies.
i've had a good look inside - nothing looks burnt, melted or otherwise damaged and the burnt smell definitely comes from the power supply.
trying to boot it up with just the graphics card and memory connected produces the same as yesterday - fans don't spool up, nothing happens except the power led lighting up - wasn't keen to keep it going for long in case there was power going to an uncooled cpu.
so, am thinking of buying a replacement power supply to see if anything is still alive - what would be a good one to go for? the current one is 400W, but i'd like to buy something a bit more powerful in case i then need to go and replace the rest of the system - probably 450 or 500W. plus, i'd like it to be as quiet as possible, but i'm on a very tight budget.
thanks again