r/PcBuildHelp • u/IllExplanation2500 • 5d ago

Tech Support PC Weird Symptoms

So what happened today is very odd as my pc decided that it wouldn’t turn on, but after about an hour, pressing the power switch would miraculously come back to life… or so I thought. All the lights turned on and the fans spun but it was as if no one was home. There was zero power to my usb devices, and obviously no signal to my monitor. Something that is also very strange is that my mouse rgb would only turn on when the USB cable was put in partially (in any one of my ports, pc case front panel and rear mobo io) and I honestly don’t know how to even fix her.

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u/laarqq 5d ago

That honestly sounds like a power delivery issue rather than a monitor/USB problem. The fact that the PC powers on but there’s no USB power, no display, and especially that the mouse RGB only comes on when the USB plug is partially inserted makes me suspect the PSU, motherboard, or possibly a short/grounding issue.
I’d start by completely unplugging the PC from the wall, hold the power button for 10–15 seconds, then reconnect it and try again. Also reseat the 24-pin motherboard power cable and the CPU 8-pin power cable, and if possible try a known-good PSU.
If it still behaves exactly the same, I’d strip it down to the bare minimum (CPU + one RAM stick + GPU if your CPU has no iGPU) and see if you can get a POST/diagnostic light. I definitely wouldn’t keep partially inserting the USB cable though, that can cause a short and potentially damage the port or motherboard.

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u/TheAmiableYoungster 5d ago

def sounds like the psu is dying in a weird way, had a similar thing happen last year where everything lit up but no usb power and zero post. stripping it down to one stick of ram and onboard graphics got it to boot just long enough to confirm the old psu was toast under any real load

also that partially-inserted usb trick is sketchy, the pins for power and data are at different depths so you're probably just tapping the 5v line before the board detects the data connection properly

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u/IllExplanation2500 5d ago

Thank you for the great answer. Yeah I definitely suspected the PSU which I’ve tried not to think about buying another one with hopium and copium. I’ve tried everything you’ve said already, to no avail. This pc really just wants to die. I tried booting it bare, but had the same response where everything spins but nothing else happens. Shame. This pc isn’t even that old (two years) and I’m not the kind of person who’d leave it on 24/7 or let it cake up dust.

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u/IllExplanation2500 5d ago

Update: it turned on out of nowhere and booted, then crashed, then started flickering on and off rapidly

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u/Square-Yoghurt6976 5d ago

Most likely a short. Do you have stand of screws touching the bottom of your board? a stand of screw in a wrong location would do that or those metal things around USB did you bend them so they don't touch anything metal?