Computer restarting every 3 secs

Hi there,
Hopefully someone here can offer help or some insight as to my computer problems.

I just relocated and packed my computer up. The hard drive was removed, and put back into the machine on arrival.
On hitting the power switch, the fans started up, lights blinked on the back of the vid card as normal.. and then 3 secs later it powers down. After about 2 more seconds, it repeats this cycle of powering up, and then powers down. Nothing is sent to the monitor and it is impossible to hit bios.

So, I proceeded to take the computer apart. I'm pretty good around the hardware, so I removed the heatsink, cleaned it out, reapplied compound and reseated it. I took out every single component and even reseated the Motherboard. The issue persisted.

Next step, I took the Mb out of the case to check for shorts. I ran it out of box with only the MB, CPU and .. actually that was it. I shorted the power switch with a screwdriver and it did the same thing again.

I've been running this setup for about 1.5 years, and I'll try to remember the components off the top of my head.

core 2 2.4
4 gigs ram
radeon 4870
750 w power supply(and a good one at that)

Thoughts anyone ?

Thanks in advance,
5 answers Last reply
More about computer restarting secs
  1. Sorry, forgot to post the information from the sticky.
    The only thing I've not done is check the errors beeps. Going to go do that right now.

    However.. if I take out the 4 pin cpu connector, then the fans stay powered on and the system does not reset. If I plug the 4 pin cpu cable back in, it continues cycling.
  2. From the sticky post:

    "Pull everything except the CPU and HSF. Boot. You should hear a series of long single beeps indicating memory problems. Silence here indicates, in probable order, a bad PSU, motherboard, or CPU - or a bad installation where something is shorting and shutting down the PSU.

    I get the long beeps.

    If you get the long beeps, add a stick of RAM. Boot. The beep pattern should change to one long and two or three short beeps. Silence indicates that the RAM is shorting out the PSU (very rare). Long single beeps indicates that the BIOS does not recognize the presence of the RAM.


    What should the next step be?
  3. sounds like a PSU.....some component is not getting the expected voltage
  4. Have you tried each stick of ram alone?

    Actually, from your description of what was done to the PC a bad PSU is not unlikely. The PSU is sensitive to shock (they often get damaged in shipping) so if the computer was banged/vibrated around this is possible. You may be able to take the PSU to a local computer shop to get it tested to see if it may be the cause.
  5. I concur, it really sounds like the PSU, which is a total bummer if you've spent a good chunk of money on a nice one. The upside is it's probably still under warranty with the manufacturer. I always keep a cheap spare (from a reputable company) around as a standby. You might try borrowing one from a friend if possible. If that's not an option I'd suggest buying a new one and/or pursuing an RMA from the manufacturer.
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