coldo

Recently my computer decided to "break" down. im in the process of changing the components of my computer to try and find the sourve of the problem. so far i have changed the graphics card, motherboard ,ram and the motherboard all of which i know work, although i am havin doubts over the motherboard. Still wheni go to turn my pc on it will start up ir processor sound comes on but the monitor will not turn on. there are no harddrives in and the power supply was faulty (i am using a new power supply now) . any suggestions??

Hi there not sure if this is the right section but i didnt no whereelse to type it. My dvd_rw has decided to stop writing discs ie it does not recognise a blank disc, it just says please insert a blank disc so i decided to open up the pc to see if anything was loose from the dvd_rw and nothing was ( i had turned the computer of at the wall before doing this) however nothing seemed to be wrong. I put the casing back on, switched the main power switch on at the back and then pressed the on button...but nothing happened it did not turn on. I opened the tower up to see that the green L.E.D light was not on even though the switch was on at the back ( idid check by switching it the opposite way a couple of times) . i pulled the power cable out and placed it back in then switched the switch now the Green L.E.D light was back on however i pressed the on button and again nothing happened. frustrated i left the computer and came back an hour later to try turning it on again, this time it worked but the computer did not "boot" up, the monitor did not turn on the keyboard functions (caps F lock and numlock would not work) so i am guessing that windows wasnot loading...then the computer voluntarely turned itself off after roughly 2 minutes. i tried turning it on again but nothing happend, when i went to switch the MAIN switch at the back of the computer seemed to turn on for a split second then turn itself of with the green light. Again i tried an hour later and it worked but same again it turned of after roughly 2 mins this time i did check to see if the fan over the processor went on as it could of been overheating but it was working fine. Ive tried unplugging power cable from back and "discharghing" the computer by holding the power button this didnt work, it is not a processor heating problem ( i dont think) this happened before when i had the fan unplugged by accident however windows loaded whereas this tme nothing. Sorry for the huge long paragraph and hope it dosnt put any1 off but the more information the better. I'd really apreciate any suggestions or input. Cheers 1.6gHz AMD athlon processor 2GB ram 240GB Hardrive