Member Avatar for stefan11

hey
My computer was working fine just yesterday, and it was working fine earlier today as well, but after restarting it, it wouldn't turn back on.

When I press the power button, the power light is on, and the fan moves for like a second but dies again. and the computer makes the boot sound... but it just won't start.
What should I do can someone help please??
Thanks

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  • Latest Post Latest Post by jingda

Dani AI

Generated

A few focused diagnostics to try before replacing the machine — concise, safe, and targeted to the symptoms described by .

  • Do a minimal "bench" boot: unplug all drives, USB devices and expansion cards; leave only motherboard, CPU + cooler, one stick of RAM, PSU and monitor. Place the board on a non‑conductive surface and power it on. This eliminates case shorts, peripherals and drive faults from the equation.
  • Rule out the front‑panel switch: disconnect the case power button cable and momentarily short the two power‑switch pins on the motherboard with a screwdriver. If the board then tries to boot, the case switch or its wiring is faulty.
  • Verify power delivery (no paperclip instructions): confirm the 24‑pin and 4/8‑pin CPU power connectors are fully seated. If you can, swap the PSU with a known‑good unit or measure the rails under load with a multimeter. Expected ranges: +12V ≈ 11.4–12.6V, +5V ≈ 4.75–5.25V, +3.3V ≈ 3.135–3.465V, standby (+5VSB) ≈ ~5V. Collapsing voltages under load point to a PSU problem.
  • Add a POST speaker and watch for beep codes or motherboard diagnostic LEDs/codes. If nothing posts and voltages look OK, the board’s VRM or CPU is likely failing.
  • Visually inspect the motherboard for bulging/leaking capacitors, scorch marks or cracked components; take photos if you post for help.

If these steps still give no POST, component‑level failure (motherboard or CPU) is likely — a local repair shop can bench‑test parts or replace caps/VRMs if economical. Safety notes: disconnect mains before handling, ground yourself, and don’t probe live capacitors. Thanks to and for earlier suggestions in the thread; these steps focus on the next level of diagnostics.

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All 12 Replies

Member Avatar for Rik_

What computer is it?

Member Avatar for stefan11

its an IBM thinkcentre pc

Member Avatar for Rik_

The first thing to do is to open it up and remove and re-fit your ram and all cards and see if that makes any difference.

Member Avatar for stefan11

i have tried the RAM already, and nothing happened
i can't re fit my graphics card because it is built into the mother board...

Member Avatar for Rik_

If you had listed what you have already tried in your first post...

The next thing to do is check the PSU. To do this, unplug it from your mobo then short the green wire to any black wire with a paper-clip or bit of wire. If the PSU doesn't fire its fan up then it's faulty.

Member Avatar for stefan11

ok I did that,
and the fan did work..

Member Avatar for Rik_

The only things left are to remove and re-fit the CPU, applying fresh thermal grease if necessary, and checking the mobo for damaged capacitors. If capacitors are blown they often leak and/or dome the end. If you spot any caps that look bad, they will need to be replaced.

Member Avatar for stefan11

hmm ok well thanks for the help
is there any chance of giving the pc a rest for a while and that it may work again in like a weeks time or so?

Member Avatar for Rik_

That wont make any difference. One other thought. Try removing the bios battery for a minute with the power disconnected from the back just in case it's a bios error.

Member Avatar for stefan11

well the battery didn't make a difference either
oh well probably have to get a new computer
thanks for the help though :)
cheers

Member Avatar for Rik_

If you have a local computer repair shop it might well be worth getting it looked at!

Member Avatar for jingda

Don't buy a new computer first. I think i can help you with it. Does your computer says monitor going to sleep and it turn off

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