Member Avatar for russey123

I have a desktop at home and it turns on for like 5 seconds and turn right back off. I leaning towards that the power supply is bad. When it turns on you can hear everything has turned of but then it just shuts right off. Nothing comes on the monitor but that because it does turn on long enough. Let me know if what i think could be it or if somthing else it bad on it.

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Building on suggestions from and , use a calm, stepwise approach to rule components in or out rather than guessing. The quickest way to isolate the fault is a minimal-boot (bench) test and a basic power-supply check. Work on a nonconductive surface, keep AC unplugged while rearranging parts, and avoid metal tools near powered connectors.

  • Safety first: unplug mains and ground yourself. Visually inspect PSU and motherboard for bulging/leaking capacitors, burn marks, or loose screws/standoffs.
  • Minimal-boot: disconnect all drives and nonessential cards. Boot with only PSU, motherboard, CPU+cooler, one known-good RAM stick, and video (use onboard if available). This narrows the fault to PSU/mobo/CPU/RAM.
  • PSU quick-test: if available, use a commercial PSU tester. Alternatively (only if comfortable), start the PSU by shorting the green wire to any black on the 24-pin to spin the fan, then measure rails on a Molex or SATA connector: yellow = +12V, red = +5V, orange = +3.3V. Acceptable ranges are roughly 12V = 11.4-12.6, 5V = 4.75-5.25, 3.3V = 3.135-3.465. Use caution — do not touch live connectors.
  • Swap or borrow a known-good PSU. A working substitute that yields stable voltages under load rules the original PSU out.
  • If PSU voltages are good, try the motherboard out of the case on cardboard (benching) to rule out chassis shorting, and double-check front-panel power-switch wiring and CMOS reset.

If no tools are available, local PC shops can bench-test quickly. When reporting back, include measured voltages, fan behavior, LED/beep activity, and which components were left connected. This speeds accurate diagnosis.

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Member Avatar for Temmu

open the case.
unplug =everything=
blow out the dust, dirt, & small animals
firmly reseat everything
try again.
(stuff needs reseated because as the pc warms then cools, the expansion / contraction pushes the cards / plugs away from where you want them.)

failing that, do you have a power supply to swap out? (use a known-good one; a new one may or may not be any good.)

Member Avatar for Serunson

How old is your computer?
And how big is your power supply?
Could be age, or could be that you don't have enough power, also how long has this problem occured for?

Member Avatar for russey123

the computer is 4 years old. My cousin gave it to me to see if i could fix it. I dont have another power supply to see if it that. I have unplugged everything. One time when i unplugged the cd drive it stayed on but i didnt hook the monitor up so i didnt know if anything cam up. I just turned it on. But now when the cd drive is unhooked it just shuts right off. I think but im not sure when i took the memory out it stayed on but it the beep because it had no memory in it but im not sure if i did that or if it was something else.

Member Avatar for russey123

the power supply is the one that came with the computer i believe it around 500 but i would have to check.

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