Computer shuts off if bumped

trev456

Distinguished
Aug 12, 2007
15
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18,510
I have been having this problem for a while and not quite sure how to diagnose the problem. If the computer is just sitting without being hit or moved, it works perfectly fine (can stay on for weeks as a time without turning off). However if you bump it with your foot and plug something into the back and move it a bit it usually just shuts off. Once it is off it will not turn back on until I wiggle the power supply cord, which makes me think it is the power supply. But I don't understand why it would do that when the cord is in there good. Any suggestions would be greatly appreciated.
 
Solution
Power cords rarely go bad unless they are stressed (under furniture, crimped, etc) so that's not likely (as you have found out).

Could be a loose connection between the PSU power cord fitting and the PSU transformer - which would mean a new PSU.

More likley I would suspect another loose connection on either an expansion card (video, modem, network, TV Tuner, etc.) or a loose power connection.

I could also be a grounding issue (weak ground on screws for mobo, power supply screws, or something more obscure).

I once had a network card that would cause intermittent power issues. Once I removed it I was golden.

Check all your connections - remove and re-seat them all - data and power. Reseat all your cards (Video, modem, network...

phantomandy

Distinguished
Apr 24, 2007
12
0
18,520
Power cords rarely go bad unless they are stressed (under furniture, crimped, etc) so that's not likely (as you have found out).

Could be a loose connection between the PSU power cord fitting and the PSU transformer - which would mean a new PSU.

More likley I would suspect another loose connection on either an expansion card (video, modem, network, TV Tuner, etc.) or a loose power connection.

I could also be a grounding issue (weak ground on screws for mobo, power supply screws, or something more obscure).

I once had a network card that would cause intermittent power issues. Once I removed it I was golden.

Check all your connections - remove and re-seat them all - data and power. Reseat all your cards (Video, modem, network card, etc.), memory, power, everything. If it's not a permanent part, remove and reseat systematically until you find the culprit.

You could also remove power and data connecitons for all non-essential hardware then reconnect one at a time and test to see if one of those items has an internal problem (non-essential would include, card readers, floppy drives, dvd/cd rom/burners, etc).

Good luck

PA
 
Solution
Dec 30, 2021
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I know it's a little bit late for this thread, but I hope this can help someone, sometime.

TLDR: The CPU needed to be reseated, and then was overtightened causing the same issue. After reseating, fully tightnening, then backing the screws out a little all power-loss problems have resolved.

I had extremely similar symptoms to OP. Small bumps and jostling would seem to completely shut off the PC. Certain times it ran normally and certain times it would need finangling just to start up. I tried messing with every cable in the machine, unplugging and reseating. I took out all peripherals including extra internal drives, anything in I/Os except power cord and monitor/mouse/keyboard when needed for BIOS etc, my whole rgb kit. I have a modular PSU so I swapped some cables and made sure they were all seated. At various random times the machine died, however I could never replicate a failure with a single action (except two firm knocks, softer than you normally would on a door, on the front of the case). Needless to say I was rather frustrated until I noticed the VGA light staying on on the motherboard. Asus recommended reseating the CPU. I did so and fully retightened my Cooler Master manifold. Now in any orientation and with any finangling the machine would only power on the obligatory amount to fully PEW back down to nothing. This I took as the first real evidence that it was a CPU seating/socket issue. After backing out the screws on my Cooler Master a few turns, the machine is running like a champ. I have knocked it quite hard several times and flipped it upside down and I am not having any loss of power. I will report if this does not seem to be the fix, but for now I am very happy with the results.

PC Specs:
Asus Prime Z390-A
Intel i7 9700K
GeForce RTX 2070 SUPER
ADATA SX8200PNP 1TB M.2 SSD
Not 100% sure on RAM but its 32GB DDR4 (16x2) G.SKILL
EVGA 750W G3 PSU