Question System randomly turns on or not working properly ?

Nov 13, 2020
I got PC with:

Gigabyte Z390 UD motherboard,
i7-8700 3.20Gz processor,
8GB ADATA 2667MHz Ram,
Gigabyte GTX 1060-G1 GPU.

The Problem is PC not getting on sometimes. When i got this PC for the first time I just turned it on, Fans are on but no display. So i Remove and re-pluged the RAM and turned on. Then the Motherboard start to loop boot. Si I remove the CMOS battery, Re-Plugged GPU and RAM again, and start. It worked. After that I could work without any problem. After I send this to my friend he said again problem occurred as previously, Some times working properly and some times no display but fans work.

This time,I have remove the remove the GPU and start with onboard HDMI but not work, again i re-plugged RAM, GPU. It work, Even It work with onboard HDMI out also. after tuned it off I tried to turn on it next day but didn't work. I take out mother board from the casing and start with only RAM. didn't work. try with ASUS 1650 super GPU not work. I change the RAM slot and start YES, it worked. So I plugged Gigabyte GPU that also work fine. I tried with turn on and off with main power.. YES it work. for the second day also work fine. I tried with another Power supply also. But no change.

Yesterday Night I kept it on BIOS setup for few minuets and got stuck. So I removed GPU and kept it on BIOS setup as previous did. Got stuck first and in few seconds colour Lines came all over the screen and changed the pattern here and there and I turned off Immediately. Today morning I Start and had boot loop 2 times and fan started to work but no display. as usual i re plugged the RAM and start Yes it working fine. I kept it on bios as Yesterday night with GPU and Onboard HDMI but it almost 15 minutes new still working without getting stuck.

What could be the Problem. GPU, Motherboard or RAM?
Last edited:
Nov 13, 2020
How do you normally shut down the PC?

PSU(s): make, model, wattage, age, condition?

Next time that the computer works look in Reliability History.

Any re-occurring errors or patterns of errors?
Shutdown using Power Icon on Start
PSU Installed: GameMax GE-700, 700W, Age nearly 1year.
PSU tried with: Newly purchased CoolerMaster NWE450, 450W

If getting on once working without No problem. Can restart. Shutdown and Start in few minutes, even can run 3D software along with many more software at once.

there is no pattern to occur this error. I turned it now after 18Hours. It's working without any problem. with old PSU, GPU, RAM and even boot windows on SSD


With the symptoms you describe it could be a bad or loose connection. Not full disconnected but loose enough to cause power interruptions.

You work inside the case and some movement causes the problem connection point to "work" again. Until it gets bumped, warmed up, or vibrates back into working again.

Power down, unplug, and open the case.

Take a close look at all power connectors for signs of damage or loose wires/pins.

Look for debris in sockets. Look for a cable/wire that is kinked, pinched, showing bare conductor.

Check the power switch as well.