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PC doesn't turn on or instantly turns off.

mniao

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PC turns on and instantly turns off

My computer was working fine just a few days ago but after I shut it off and tried turning it on the next morning it refused to turn on.

The only way for it to give any sign of life is if I completely turn the PSU off for a few seconds and try to turn it on again which causes the computer to light up once for a fraction of a second then turn off again.

I tested the PSU with the paperclip test thing and it turned on.

What I've tried doing:
1. Turning it off and holding the power button for 30 seconds.
2. CMOS Reset.
3. Tried removing GPU, HDD, SSD
4. Tried running with just one stick of ram (Tried both slots).
5. Tried turning it on with a screwdriver.
6. Tried replugging the PSU cables.

SPECS:
MOBO: B450M DS3H
PSU: EVGA 500W BRONZE 80 PLUS
SSD: Lexar 1tb nvme m2
CPU: Ryzen 5 1600
GPU: Geforce RTX 2060 12GB
 
While there is certainly potentially a hardware problem...

Have you tried unplugging the Power and Reset switches? A stuck/shorted/failed power or reset switch could be causing this sort of problem.
If you have a steady hand, you can 'short' the power-on pins w/ a screwdriver, etc. (for a moment) to manually test power-on w/o a momentary switch.
 
While there is certainly potentially a hardware problem...

Have you tried unplugging the Power and Reset switches? A stuck/shorted/failed power or reset switch could be causing this sort of problem.
If you have a steady hand, you can 'short' the power-on pins w/ a screwdriver, etc. (for a moment) to manually test power-on w/o a momentary switch.
I've already tried shorting the power pins and it only leads to the same results sadly.
 
PC turns on and instantly turns off
test the power output voltages are at the correct voltages

it might be as simple as a power supply issue
 
have you tried turning on just the PSU, completely unplugged from everything

if it comes on and has power, then test the power outputs are at the correct voltages

it might be as simple as a power issue
Yeah it turned on normally while doing the paperclip test thing, how do I check if it's outputting the correct voltages? I don't have another system or PSU available
 
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Just based on the things you've tried thus far, my mind would be leaning towards the motherboard.

CPUs very rarely go bad, but that's another possibility.

The PSU is another possibility, although the fact that it's turning on by itself is a good sign (but doesn't guarantee it's not the problem, as it could even be a cable).

You took the storage and graphics out of the equation and the issue remained so it reasons it's unlikely to be one of those.

You tested different RAM in different slots. This should reasonably rule that the RAM/RAM slots are good?

That leaves the motherboard, CPU, and PSU (and its cables). I would do as others suggested and really minimize it further if you can by taking it out of the case and disconnecting fans to rule out a short. If you had a spare PSU, that would really help as I think its likely to be between the PSU or motherboard.
 
Yeah it turned on normally while doing the paperclip test thing, how do I check if it's outputting the correct voltages? I don't have another system or PSU available
use a volt meter and test for correct voltage, yes its a very basic test, but its all i can think of

if you arent getting 5v or 12v to all wires you are supposed to read 5v or 12v, this will tell you

just be sure if you buy a voltage tester, that it goes up to 50v DC, since many of the cheap testers under $20, only test up to 4-5 dc volts
 
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Try powering up without CPU ATX power plugged in. If it runs, then CPU or CPU VRM is fried.

It not, then look on secondaries, bottom board. I hope at least you took out the battery tried to run without it.
 
If you think it is a short or fried VRM, you think OCP is triggering it to power off. Problem is, it doesn't turn off if they jumper it. So, unless the OP is also disconnecting everything in the jumpering process, nothing which is connected could be the source of the short.
 
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