Member Avatar for ledzepp

Strange.. I installed everything on my motherboard, everything is perfectly set up and when I turn the power switch the fans and everything starts moving for a split second and then turns off.. 3 seconds go by and the fans start moving again, then it stops... and on it goes. I was afraid this would damage my components so I turned my computer off and rechecked everything. Everything was correctly put in place. Here are my computer specs!!



Corsairs 4x1Gb Ram
ASUS P5N-E SLI LGA 775
FSP Group AX500-A ATX12V 500W Power Supply
Tuniq Tower 120 P4 & K8 CPU Cooler - Retail
Western Digital 320GB 7200 RPM SATA 3.0Gb/s Hard Drive
PNY GeForce 8800GTS 640MB 320-bit GDDR3 PCI Express x16
DVD Phillips Burner

So there it is... I dunno what the problem could be. The only thing I could think of is that the power supply not giving out enough power for that huge video card. Could that be it?! Thanks for your opinion guys!

Jerr

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Short cycling like "fans spin for a second, then everything dies, repeat every ~3s" most often means the power delivery or a detected short is forcing the system to shut down immediately. Common culprits (in order of how often they show up) are: the PSU tripping on over‑current/short, a motherboard short to the case or a misplaced standoff, a bad/missing 4/8‑pin CPU power plug or PCIe power to the GPU, a faulty front‑panel power switch/wiring, or a defective component (RAM, GPU, board, PSU). BIOS/CPU compatibility can also cause no‑POST behavior, but it usually won’t produce a steady on/off cycle like this.

Follow ’s minimal‑system approach but with a few more checks and cautions. Power down and unplug, then test with only the essentials: CPU + cooler, CPU 4/8‑pin and ATX 24‑pin connected, one known good stick of RAM in the recommended slot, and GPU if no onboard video. Remove HDDs, optical drives, extra cards, USB devices, and front‑panel USB/audio headers. Attach a small chassis speaker for beep codes. Power on: if it still cycles, the problem is most likely PSU/motherboard/short.

Concrete checks to do next:

  • Verify the CPU 12V and main 24‑pin are firmly attached and not using split/adapter cables.
  • Confirm the GPU’s PCIe power cables are connected.
  • With the PSU unplugged, inspect for misplaced standoffs/screws touching the motherboard; test the board outside the case on cardboard/anti‑static bag.
  • Try a different (known‑good) PSU or a PSU tester rather than guessing wattage—quality and rail amperage matter more than a label.
  • Temporarily bypass the case power switch by shorting the two power‑header pins briefly (use a non‑conductive method or a screwdriver carefully) to rule out a shorted switch.
  • Reset CMOS (clear jumper or remove battery) and reseat RAM; try each RAM stick alone.

’s note about listening to the hard drive is sensible: a dead drive shouldn’t normally force power cycling, but a failing drive drawing abnormal current or a shorted drive PCB can contribute—disconnect drives while testing. If none of the above isolates it, the most likely outcomes are a defective PSU or a faulty motherboard; swap with known‑good parts or take the machine to a shop for bench testing. Follow basic ESD safety and do not open the PSU.

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Member Avatar for verbob

Unplug everything except CPU, One stick of ram and video. If it posts, then try adding one thing at a time to try to eliminate what is causing the problem.

If not...well...either one of the components are bad(yes it is definately possible to have a new component dead right out of the package) or just incompatible in that configuration.(for example - the Motherboard may support the cpu, but only after a BIOS upgrade...)

Member Avatar for ledzepp

Unplug everything except CPU, One stick of ram and video. If it posts, then try adding one thing at a time to try to eliminate what is causing the problem.

If not...well...either one of the components are bad(yes it is definately possible to have a new component dead right out of the package) or just incompatible in that configuration.(for example - the Motherboard may support the cpu, but only after a BIOS upgrade...)

Hmm, so its not the PSU causing the problem? I would've thought that all these components were giving a heavy load to the PSU, thus causing the computer to turn on and off.:confused:

Member Avatar for verbob

Well, it still *could* be the PSU...but a NEW 500W should have more than enough juice to atleast see post.

Member Avatar for verbob

Just thought of something (alot of people forget about this - I've done it a time or two myself) Make sure you have POWER PLUGGED INTO the video card

Member Avatar for ledzepp

Just thought of something (alot of people forget about this - I've done it a time or two myself) Make sure you have POWER PLUGGED INTO the video card

Yea, its plugged in. The video card's not the problem, the problem is that the compter keeps turning on and off. So I'm guessing its just too much power for my PSU. Not sure though, Im still waiting till I get home to try and turn this thing on with the basics.

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