Question Mystery PC Reboot/Restart

[Mikhayil]

My PC has been randomly restarting for months now and i have not been able to use it, i have tried almost everything to diagnose the issue however i can’t seem to find it - It was working for a year perfectly until one random morning
The PC will restart in any condition of being on ( In Bios, before password entered, even go into a restart loop after a while). In the beginning the restarts occurred after a while of turing on (1 hour) however now they occur very randoml .
I have:
Bought new PSU and tried it
tried different GPU
tried removing Power and restart buttons
tried different residences (in case of house power)
Tried all different periferals
Tried using the RAM sticks singularly and in different ports

The weird thing is i took it to a PC repair shop (centrecom) and they had it for a few months in and out and said they couldent replicate the fault even once (when i brought it back it happened again) - i speculated they lied however they seemed very genuine

I have had recent headway when i removed all the case fans and USB lines from the motherboard along with the keyboard and mouse and the PC STOPPED restarting. As soon as i plugged the mouse back in the PC restarted (tried different mouses before and same issue so it’s not the mouse)
I’m guessing it’s somthing got to do with motherboard power or somthing like that but i’m no expert, any ideas? please help

 

[rgd1101]

full system spec? include brand and model of the psu

 

[Mikhayil]

AMD RYZEN R5 3600, 6C 12T, 35MB CACHE, 65W TDP

ASUS DUAL GEFORCE RTX 2060 OC EDITION EVO 6GB GRAPHIC

CORSAIR 16GB KIT (2X8GB) DDR4 VENGEANCE LPX BLACK C20 3600MHZ
GAMING RAM

SAMSUNG (970 EVO) MZ-V7E500BW 500GB, M.2 INTERNAL NVME PCIE
SSD, 3400/2300W MB/S. 5YR WTY

COOLER MASTER MWE 80+ GOLD, 750W. FIXED CABLE. COMPACT SIZE
WITH 12CM FAN

MSI B450 GAMING PLUS MAC AMD MOTHERBOARD

BRAND NEW PSU - Gigabyte 850 watt gold rated modular PSU

 

[alceryes]

Check all I/O ports - especially USB. Make sure none of them are damaged.

Are you using the same UPS/PDU/surge protector? If yes, try a different one or, temporarily, plug directly into the wall for testing.

 

[CompuGuy71]

I'd make sure every connection is firm on your Motherboard, especially with a new PSU and all the work you've been doing in your PC lately. Just make sure everything is seated properly.

 

[Mikhayil]

I have tried completely different residents with surge and no surge protector. The rear I/o ports appear to be fine.

 

[Mikhayil]

I'd make sure every connection is firm on your Motherboard, especially with a new PSU and all the work you've been doing in your PC lately. Just make sure everything is seated properly.

Have done, but i only got the new PSU after the problem, so it’s not got to do with seating

 

[CompuGuy71]

Are there any random cords across your motherboard? I have seen where somehow a fan cable or something of that nature is able to touch the motherboard pins and jump them just right to force a restart.

 

[alceryes]

I have tried completely different residents with surge and no surge protector. The rear I/o ports appear to be fine.

Front/side I/O ports? (depending on case)
Have you checked the motherboard for distended/leaking capacitors?

 

[Mikhayil]

Are there any random cords across your motherboard? I have seen where somehow a fan cable or something of that nature is able to touch the motherboard pins and jump them just right to force a restart.

No, this has been a problem for months and i have been frequently checking everything, the only reason i’m suspicious of the mob is that when i unplugged almost all connections to it it worked fine for the longest in a long time then almost exactly when i go to plug in the mouse it restarts? Like the power draw from the mouse was too much for it?