Hi, Im new & dont know too much about computers. Heres my problem: I have an AMD Athlon XP 2400+ & whenever i play games it restarts itself, i deceided to see what temps i was getting after it restarted & they where in the 80's. So i bought myself a new heatsink & fan (http://by101fd.bay101.hotmail.msn.com/cgi-bin/getmsg?msg=F3E74D7D-1D25-4E18-94F7-EF64FA6D815E&start=0&len=26005&msgread=1&imgsafe=n&curmbox=00000000%2d0000%2d0000%2d0000%2d000000000001&a=04549f9062e3e58e70b8bea018dbb4c2881ac6a9c04fdf4c4a6207c6e6731db6)

When i tried to install the heatsink & fan i noticed that the new one was bigger than the old one but it fitted so i carried on anyways, once it was installed i tried to boot up the screen did not come on, so i tried fitting the H & F the other way, but still with no luck. So i took off the new H & F and fitted the old one, but when i tried to boot the power would come on for a few seconds and then switch off.

I really dont know what to do, i dont have any power on my pc & am thinking of buying a new one, but would rather save myself the money & get this one fixed..

Did you use thermal paste on the Heatsink/CPU interface when you attached the new one? CPU's dissipate upwards of 80W these days(ever touch a 100W light bulb when it's on?). If the H&F aren't installed correctly it will over heat the CPU in seconds. Remove the H&F and CPU again and carefully inspect the pins for damage, DO NOT touch them unless you are properly grounded! Reinsert the CPU and ensure the locking lever is closed fully. Follow the H&F manuf installation instruction using thermal paste. The heatsink MUST be absolutely flush with the surface of the CPU. DO NOT remove the little rubber feet from the bottom of the heatsink, if you do, you can crack your CPU.

Good luck

i did put thermal paste on, the rubber feet are still on the heatsink. I turn the power & it stays on but nothing comes up on the monitor, i also dont hear any beeps when starting up..

Well hopefully it's a loose connection somewhere and not a fried CPU. Are all the fans coming on, any lights on the HDD or mobo? It is possible the new fan unit over taxed the PSU and killed it. No biggy those are easy enough to replace for $30-$40 US.

Remove and reseat your RAM and video card. Can you boot into BIOS screen?

It swtches on, but nothing comes up on the screen, i dont get any beeps or anything, the fans & everything comes on though..

Well it's sounder closer like a CPU failure. If you remove your RAM, does the mobo beep? What I'm trying to determine is if you have a partial PSU failure and your mobo is not getting proper voltage. With the RAM removed it should beep on power up. If no beep then there's a good chance it's just your PSU.

If you get beeps, then do a CMOS refresh (mobo jumper, or pb switch, or remove the battery for 30 minutes). Then keep fingers crossed and try it again.