Member Avatar for Dand321

My computer froze up yesterday, so I couldn't restart from the shutdown menu and had to turn it off by the switch...when I pressed the switch to turn it back on I was getting nothing, after pressing it several times it will turn on and try to boot up with all fans and harddrive seemingly starting normal and then after 2-3 seconds it just shuts down...any suggestions

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  • Latest Post Latest Post by sirlink99

Dani AI

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Rapid on/off after 2–3 seconds is usually a protective shutdown rather than an OS problem. Common root causes are a PSU rail collapse under load, a motherboard short or failed component, missing/incorrect CPU power or fan detection, or a bad soldered capacitor on the board. Since reported a paperclip test and that fans/HDD spin, note that a paperclip only proves the PSU will spin up — it does not prove stable voltages under CPU/GPU load. ’s front-panel fix demonstrates the simple-case possibility, but because shorted the power‑switch harness with same behavior, the fault is more likely PSU/motherboard/CPU related than the case switch.

The following checks help isolate the fault (power must be unplugged before touching anything):

  • Visually inspect motherboard and PSU for bulging/leaking capacitors, scorch marks, or a burnt smell.
  • Confirm the ATX 24‑pin and the 4/8‑pin CPU (ATX12V) power connectors are fully seated.
  • Verify the CPU fan is connected to the CPU_FAN header and actually spins; many boards will cut power if no tach signal is seen.
  • Attach a PC speaker or speaker jumper to hear BIOS beep codes during POST.
  • Perform a minimal-boot: remove drives, cards and extra RAM, leave CPU, one RAM stick and GPU (or remove GPU for onboard video) and attempt power. Note whether behavior changes.
  • Swap in a known-good PSU or use a PSU tester/multimeter to verify +12V/+5V/+3.3V under load; the paperclip test is insufficient.
  • Breadboard the board outside the case to eliminate standoff or case shorting.
  • Clear CMOS (battery out 5–10 minutes or use jumper) to rule out corrupted BIOS settings.

If minimal testing points to unstable rails or visible capacitor damage, motherboard or PSU replacement is the practical next step on an older P4 machine. If uncertainty remains, professional diagnostics are advised for safety and to avoid component damage.

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Member Avatar for Rik_

We would need to know what computer it is before making any suggestions!

Member Avatar for Dand321

We would need to know what computer it is before making any suggestions!

My computer has a Penitum 4 Processor, we built it for video type work, so it beefed up...I did paper clip test and the PSU seems to be okay, I've checked connections and all seem to be tight.

Member Avatar for Rik_

Is it a home build or a shop bought machine? When you say you did the paperclip test, please describe exactly what you did and what you tested.

Member Avatar for blujaded

I had the same problem with mine. It would restart randomly, sometimes before post and sometimes 20 minutes or 2 hours later. Sometimes it wouldn't restart at all, but just shut off. Basically made my comp useless! I tried everything - replaced the PSU, checked all connections, check hd for errors and reinstalled Windows. Still had the problem. Took the front panel off and checked the power switch. One of the clips that holds it in place had broken creating too much 'give' so when the button pushed the switch it couldn't make full contact. The switch was wigging out. Took out the button and now it works great. Not the ideal solution, but at least the restart issue is fixed!

Member Avatar for sirlink99

Mine has a same type of error. When I start it up in the normal power setting it turns the fan for like a second then turns off, when I put it to a higher setting the comp turns on, but there is not video out, so I don't know what it is doing. at first I thought it was the power button, so I removed the cords to it, and touched them together, same problem.

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