Question Monitor signal cuts out at random times

[Centurion855]

Hello everyone,
I have a very annoying issue which makes my monitor signal cut out and display the message "no signal" at random times. This can happen 3 times per day but sometimes it's also fine for 2 days in a row. My monitor screen will freeze for 2 seconds, then it turns black and displays the message "no signal" while the audio keeps going. The only thing I can do to fix this is press the reset button on the front of my PC to restart my PC.

This can happen during gaming, but also in outlook while writing emails or watching youtube videos. I do notice that when i'm gaming like for example in games such as Anthem & Rust it happened more often than normal desktop usage.

Things I have tried to troubleshoot this issue:
- I had my MSI GTX 1080 Ti tested at a hardware shop and with tests they detected it was faulty, I had it RMA'd and repaired by MSI.

- While my GTX 1080 Ti was sent to MSI to have it repaired under warranty I had a basic temporary replacement graphics card: an Asus GT 710. The issue even still remained with this card.

- I tried switching my current monitor which is is an Acer Predator XB281HKbmiprz connected via Displayport with my old Samsung Syncmaster Samsung S24B350H 1080p monitor which was connected with an HDMI cable. The issue still remained to my surprise.

- They also gave my old power supply a Corsair HX1050 a quick test with a little measuring device and it quickly indicated a "failure" that it could not deliver sufficient power. I had this power supply also replaced by a new one which is the Corsair HX750i

- I tried to turned down the overclock on my i7 4930K of 4.3Ghz back to stock speed which is 3.4Ghz. I always monitored temps using RealTemp and while doing heavy stress test with IntelBurntest and Prime95 it did not exceed 85°C with my Corsair Hydro H100i water cooler so I assumed my overclock was decently safe temperature wise. I even still have a screenshot of the 4.3Ghz overclock stress test and CPU-Z validation report of 4.4Ghz.

- I have monitored the temperature of my GTX 1080 Ti and while gaming the temperature stays around 65-70°C.

- I have monitored my RAM usage and it rarely goes above 11GB/16GB usage while gaming and having steam, discord, firefox, media player open. So I think I have enough headroom with my RAM as well.

- I have fully cleaned my PC from all dust with a compressed can of air and cleaned all the dust filters thoroughly.

This kinda rules it it's probably not my monitor, graphics card or power supply so maybe it is my CPU or RAM which is causing instability making my monitor signal cut out at random times? Maybe my CPU which did run overclocked for a long time (1 year+) has caused instability somehow? Does anyone have more ideas to further troubleshoot my issue and find out what is causing this no signal problem? Any help is much appreciated !

My full PC specs:
CPU: Intel Core i7 4930K
CPU Cooler: Corsair Hydro Series H100i
Mobo: Asus Rampage IV Black Edition
RAM: Corsair Dominator Platinum 16GB DDR3-1866Mhz CL9 quad kit
GPU: MSI GTX 1080 Ti Lightning X
SSD: Samsung 840 Evo 1TB
HDD 1: HGST Deskstar 7K4000 4TB
HDD 2: HGST Deskstar 7K4000 4TB
ODD: LG BH16NS40
PSU: Corsair HX750i
Case: Cooler Master Storm Trooper Window
OS: Windows 10 Pro 64-bit
Monitor: Acer Predator XB281HKbmiprz connected via Displayport (running on native 3840x2160 resolution with Nvidia G-Sync enabled)

 

[COLGeek]

Have you tested your memory with a tool like memtest? Also, are you overclocking your memory?

 

[Centurion855]

Have you tested your memory with a tool like memtest? Also, are you overclocking your memory?

I actually have not tested my memory yet, I will google how to do it and with which tool and i'll reply here in this thread. Now my memory is not overclocked anymore but before when my CPU was overclocked to 4.3Ghz my RAM was also automatically overclocked by the Intel XMP profile setting in the BIOS.

 

[COLGeek]

I have used this tool many times, over the years.

Memtest86+ | The Open-Source Memory Testing Tool

Memtest86+ is an advanced, free, open-source, stand-alone memory tester for 32- and 64-bit computers (UEFI & BIOS supported)

www.memtest.org

 

[Centurion855]

I have used this tool many times, over the years.

Memtest86+ | The Open-Source Memory Testing Tool

Memtest86+ is an advanced, free, open-source, stand-alone memory tester for 32- and 64-bit computers (UEFI & BIOS supported)

www.memtest.org

Yes, that is the one I used. I created a bootable USB flash drive and ran it from there.
I did not have the time right now to let it complete 4 total passes of the memory test but one fully completed and that one gave no errors. I took a picture of the test screen & summary of it with my smartphone:

One weird thing that happened was that when the first time I ran the test, I plugged in my smartphone in my KiDiGi docking station while it was running the memory test and then I immediately got the "no signal" message and my screen went black as usual. After that I pressed the reset button, booted from the USB disk and started a new memory test and then it did not give the "no signal" message. Now I'm not sure if the very first time the test caused the "no signal" message to appear or because I put my Galaxy S9 smartphone into my KiDiGi USB docking station... I will for sure do the test again later when i'm away from home or something to see if it can complete 4/4 test runs with succes.