new pc errors :(

[masterg]

i just got new parts in to upgrade a 7 year old dell of mine, im turning it into a custom build:
some amd sempron 64bit mobo; goal 3+ sis 761gx 965L
EN7200gs asus 256 video
Maxtor 80gb hdd
amd sempron 3000+
512 kingston DDR 400 RAM
cdrom, floppy

this is my back up pc and it sux by default, but
its has a 350W PSU and the HDD has bent prongs and somethings falling off;

when i start it up it turns on, and goes to a windows startup selection, i click start windows normaly and then the computer shuts down and reboots and i dont know whats wrong, whether its a weak PSU or something with the hdd

i i have a 450watt psu i hooked up to it but the fan doesnt run so i think its broken, i put in the windows cd to preform a repair installation and the computer powered off before i got anywhere, went out for some food came back and now when it starts up i dont get a video picture

please help

[ski]

Suspect a weak PS.

[blue60007]

What brand is it? Do you have a spare one that works for sure?

[flanzig1]

Sounds like a possible CPU overheating issue. Would check to make sure that the CPU heatsink is on tight and correctly/CPU heatsink fan plugged into the motherboard and if the CPU and/or the heatsink are from another system that the old thermal compound was cleaned off the CPU face and the mating surface of the heatsink. And then a fresh thin layer of thermal compound applied to the face of the CPU.