My desktop computer was working normally yesterday, but today it powers on for a couple of seconds, shuts off, and immediately tries to start again. It keeps repeating this cycle. I already checked whether it might be drawing too much power, but nothing seemed unusual. What should I check first to diagnose the problem?
3 Answers
Try a different known-good power supply if you can. Also check the motherboard for diagnostic LEDs or beep codes; the manual should explain what each pattern means. Make sure the motherboard power connectors, CPU power connector, RAM, and graphics card are firmly seated. A short circuit, failed power supply, bad RAM, or motherboard problem can all cause this restart loop.
If it stays powered on long enough, try entering the BIOS setup using the key shown during startup, often Delete or F2. If it can remain in BIOS without restarting, the issue may involve the operating system or a boot device. If it still shuts down while sitting in BIOS, focus on hardware, especially the power supply, RAM, CPU cooling, and motherboard. Avoid repeatedly powering it on if you notice overheating, burning smells, or unusual noises.
Start by reducing the system to the bare minimum: motherboard, CPU and cooler, one stick of RAM, power supply, and graphics only if your processor lacks integrated graphics. Disconnect storage drives, USB devices, and other peripherals. Then test the RAM one stick at a time and try different memory slots. This can help identify a faulty component or connection.
I unplugged everything except the power cord, but it still wouldn't start normally.
Checking the exact motherboard, CPU, RAM, power supply, and graphics card models would help narrow this down. It also matters whether the system stays in the loop indefinitely and whether you hear any beeps or see flashing error lights.