PSU Problem?

Hey i'm not sure whats causing this problem but I think its the power supply. At random times my whole computer will just power off with any warning or anything. It just shuts off, at first I though it was heating so i took the side of my computer off and blew a really really big fan into it. and it keep doing it so i checked the temp of the computer and it was around 66 c. Then I though the ram was bad so I sent it back and got new sticks and i'm still having this problem.

I have a 500 watt Power supply right now, but I have a lot of lights plugged into it so maybe thats causing the problem. if anyone has any ideas of whats causing the problem please let me know thanks.

Are both fans running, the one in the PS and the one near the CPU?
That's the first thing to check.

Yes - the fans are working over time. Even if i leave the side of the case on and it overheats, it'll sound like a jet taking off with the fans going full-speed, but will never crash.

it might be the thermal paste on the CPU

It sounds like the PS fan has a bad bearing and that's what is causing the jet sound.

when I go into my system bios under computer health. it says +12 volts failed. and I got speed fan and under +12 volts it dont say anything, so would that be the MB or the PSU

The power supply that supplies the voltage to the mother board, so if the voltage failed, I would guess the power supply.

Also, when you're not sure what the problem is and you have to guess, you always replace the least expensive part and in this case, a power supply is cheaper than a mother board. I use that same idea no matter if I'm fixing a car or whatever.

Ok, I found a thread nearest my questions...

It has to do with Power Supplies...

What wattage would one go with 2gigs of memory and a AMD 5200 AM2+ processor and AM2 Mobo... with a decent video card? 430W? 500W?

How much would you reccommend on spending on a power supply for a computer?

Other specs: 350 SATA 3.5" Harddrive and a DVD/CDR/RW Drive

I plan to read alot of reviews because I just simply do not want a fire and I haven't successfully built my first computer yet. I don't know what's safe as to if you can power up your computer unless what components are missing. I didn't have the processor yet, but I simply wanted to test the LED's in the case and fans and see if they worked properly and poof went my power supply that came with my case.

Also, know any good sites with good in detail instructions for building an ATX style non-gaming computer really, just simple and not obsolete for awhile.