[SOLVED] PC randomly shuts down without any pre-warning

[XGamer_BiH]

Hello folks,
lately I have been experiencing issues that my PC randomly shuts down, without any pre-warnings or such.
This happens 99.9% times during playing games.

- Firstly, I measured the GPU and CPU temps during gameplay, both stayed inside their limits.
- Secondly, measured 5V voltage on a 4-pin molex cable, and the voltage didn't drop under 5.1V the whole time. Why 5V output? Well, I noticed that sometimes my PC would refuse to start after the crash UNTIL I plug out ALL USB ports, and then it can start - sometimes won't even start, sometimes starts and shuts off after few seconds - it usually varies. Also, I noticed that whenever I touch the USB male cable on the backplate of my case I can see arcs 60% of the time I touch the frame/case.
- Thirdly, my PSU doesn't create any weird smells, the fan works fine and all the voltages are stable.
- Fourthly , I stress tested my CPU to simulate some of the load during gameplay, and it went just fine, no issues at all.

Note: there are BSODs and/or messages after the startup after the crash.

(may be weird, but I noticed that ever since I bought a 2.5"HDD to USB adapter, this started happening - also I noticed that in 40% of time, the adapter from the drive to USB wouldn't want work, ONLY on my pc, I tested it on a different PC, a TV and even a phone charger - all worked fine, but my PC not.)

Specs:
Asus H61M-C
i5 3570 stock
8GB DDR3 RAM
LC Power LC600H12 PSU
HDD and SSD drived installed

 

[Ralston18]

" Also, I noticed that whenever I touch the USB male cable on the backplate of my case I can see arcs 60% of the time I touch the frame/case."

arcs? You mean sparking - correct?

If so, there is a short. Try another known working USB cable.

And if the problem continues take a close look at the arcing USB port for damage or some misalignment allowing metal to metal contact. (Could be a damaged plug on the current USB cable as well.)

 

[XGamer_BiH]

" Also, I noticed that whenever I touch the USB male cable on the backplate of my case I can see arcs 60% of the time I touch the frame/case."

arcs? You mean sparking - correct?

If so, there is a short. Try another known working USB cable.

And if the problem continues take a close look at the arcing USB port for damage or some misalignment allowing metal to metal contact. (Could be a damaged plug on the current USB cable as well.)

That sparking happens only with one cable, and it's from my Logitech Driving Force GT steering wheel, I believe that's because the wheel is constantly connected to a power adapter since it has additional motors for force feedback. Also I noticed that thos sparks cause the PC to wake up from sleep. Plugging out the power adapter stops the sparking.
But, my PC shuts off not depending on if the steering wheel USB is connected or not.

Also, I noticed that taking my left case panel off makes the shuts down less often - another extremly weird thing that can't be explained...

 

[Ralston18]

There should not be any sparking at all.

It is good that you have been able to narrow down the source to the steering wheel/ power adapter.

Ultimately, since the steering wheel is not a "source" of power, the culprit is likely the power adapter. And if the problem is constant via the steering wheel's cable then there is a short in the steering wheel or its' respective cable.

However, if the problems continue even without the steering wheel and/or the left case panel being present then I would be thinking about a grounding (earthing) problem with the wall outlet(s) serving your setup.

The voltage could be coming via some other device.

Isolate and start testing other voltages and grounds.

 

[XGamer_BiH]

There should not be any sparking at all.

It is good that you have been able to narrow down the source to the steering wheel/ power adapter.

Ultimately, since the steering wheel is not a "source" of power, the culprit is likely the power adapter. And if the problem is constant via the steering wheel's cable then there is a short in the steering wheel or its' respective cable.

However, if the problems continue even without the steering wheel and/or the left case panel being present then I would be thinking about a grounding (earthing) problem with the wall outlet(s) serving your setup.

The voltage could be coming via some other device.

Isolate and start testing other voltages and grounds.

Thanks!