My computer won't start.

[clueless1]

I have a V2 Premier desktop. (about 5 yrs. old) A few weeks ago I noticed a strange noise which I think was the fan when I first started my computer. Yesterday, I started my computer and it stayed on for approx. 45 sec. to a minute. It then shut down with no warning. I started it again and it stayed on for about 30 sec. I waited awhile, and started it again and it ran for approx. an hour before shutting down. It would not start after that. I took the power supply in and it checked BAD. I bought a new one. My old one was a wimpy 150 watt and they didn't even carry those, so I bought what they had which is a 450 watt. Now, when I attempt to power up, the lights on the front of the tower light for a second, the LED on the motherboard lights for a second and the fan spins for a second and then it shuts down. In order to get power back to the unit, I have to turn the main switch off and back on again. Does anyone have any ideas as to what the problem may be?
Thanks,
Clueless1

 

[N3051M]

-take extra attention to the cpu heatsink and fan - when you turn the power on does it spin up? maybe extreamly cloged up with dust etc?
- check your motherboard documentation on the recomended Amps rating for the PSU to output
- complete pc specs please

with pc unplugged from the mains:
- touch the pc case to discharge any static built up in your body.
- clean out your pc from dust. You can use a compressed air (at petrol stations for doing the tyres or a can of compressed air, not deoderant cans or anything of sort) or a vaccum cleaner
- check all your wireing and power connectors are on properly, no shorting to anything
- reset the CMOS by jumper or taking the battery out for a few seconds
- check that the PSU is set to your country/area voltage rating (240v/120v)

if still no go:
unplug all devices exept the basic so you should have: motherboard, psu, video, cpu and sound. power up and see if you can access the bios. check all settings are correct, in hardware monitors, check temperatures not hot (20-40 good, 50-60 warm/hot, 60+ DANGER!!!) if it is note which one and post back. check also the voltage given with the PSU on the same screen.
If all ok, start plugging in 1 device at a time, untill you find the culprit.

 

[clueless1]

Thanks.

Thanks a lot for the info. Will try these things and see what happens.

Clueless1