Blank screen or no signal during MemTest86

[bladE_666]

I'm unable to complete MemTest86 as the monitor will shut down after few hours or significantly shorter time period with discrete GPU. I haven't received any reported memory errors so far and the computer seems to be okay in daily use. Other bootable memory test utilities will behave pretty much the same, but memory seems to be stable under Windows while testing it more than eight hours.


MOBO: MSI GAMING PRO CARBON AC (MS-7B17)
CPU: Intel 8700K
RAM: 32 GB of HyperX HX436C17FB3K2/32

[David (PassMark)]

There is nothing in MemTest86 that turns the monitor off and it isn't something we see on any of our test systems. Can you try a different monitor.
But if you have already tested for 8 hours and found no errors, then the memory is probably fine.

[bladE_666]

Thanks for your information. Desktop utilities may not be as good as bootable alternatives, so I was slightly worried about this blank screen problem. Obvously UEFI BIOS doesn't allocate any RAM and writing to memory is safe and therefore can not cause a such issue? It seems that the MemTest86 is still running properly despite the blank screen issue.

[bladE_666]

I was finally able to run the tests successfully without losing the display signal. Replugging the DisplayPort cable does not help, but disabling DP deep sleep from the monitor options did the trick.

Of course the display isn't absolutely needed for MemTest86, but if something unexpected will happen, it should be considered as a potential stability issue until further explanation. This is the case when spesifically testing the hardware.

[David (PassMark)]

Thanks for the update. It might help someone else with the same problem.

[Wolverine2349]

I can chime in on this now that I saw it. I wonder and actually believe if the DisplayPort signal is just flakey during the UEFI/BIOS portion of screen on some video card/monitor combos.

First time I had DIsplayPort connection was with a GeForce GTX 1080 in 2016. It was on a Asus Sabertooth Z97 motherboard then a Z170 mobo The monitor was an Acer Predator 144 Hz 1440P display. Sometimes in the UEFI BIOS on both boards the signal would just go blank and you would have to reboot to fix it. Sometimes unplugging and replugging it in would fix the problem, but sometimes not and would hve to reboot. But the computer was stable and no issues in BIOS or on POST. This would also happen in Windows before GeForce driver was loaded.

It also happens in MemTest86 especially if I decide to just turn monitor off and let it run for around 1 hour or more. I turn monitor back on and nothing. But MemTest I think is still churning along on my new 12700K with 32GB DDR5 6200MHZ keeps testing. I believe this because the post code on the motherboard is the same. I also know you can just hit the power button in MemTest and it will shut off your system right awat just like on BIOS or post Screen. Same thing happens when monitor gets no signl.

I have had times where it truly is not stable testing overclocks where monitor gets no signal, but Power button on PC does not shut off computer and you have to manually switch power supply off to get it to turn off. SO I think that would happen with MemTest86 if it were not stable.

In fact I had a X570 Gigabyte Aorus XTREME AMD Ryzen 5900X system where I ran some Crucial Ballistics RAM 3600MHz with tighter timings at increased VCORE than spec RA was rated for. MemTest86 never gave an error, but the screen would go blank and system was unresponsive and system seemed to make a reboot with a changed code or something and would have to manually power off PSU. And it was not just MemTest. In Windows running Prime95 Large FFTs with AVS disabled test would hum along just fine then system would freeze and screen would go blank. Had to make memory back to rated timings and things were fine.

SO its probably ok. if it is just the Display that goes off. In fact with a perfectly stable system, my display would sometimes turn off and I would have to unplug and replug cable to get it back on. Perhaps it is the DIsplayPprt monitor or signal to video card or vice versa not totally stable in such situations Maybe due to generic driver (Like UEFI BIOS or MemTest) or even official NVIDIA driver in WIndows??

[David (PassMark)]

If you aren't sure if MemTest86 is running (because the screen turned off) you can check the debug log file later on the USB drive.

And yes, having the screen go blank can mean several things (monitor going to sleep, a crash / reboot, or a lockup, bad monitor cable, bad video card, bad monitor, BIOS bug that results in some video modes not being available, etc..).

[acratone]

I have 2 monitors connected to my PC.
Same thing happened to me Memtest86 booted up and showed up on screen, until test started, and then the screen went to black.
The way I solved the issue was to unplug one of my monitors and reboot the system.
Then it worked OK and everything showed up on the screen during the test.
The one I unplugged of course was the one the test ran on in the first place when the screen went dark.
After completing the test I plugged back in the 2 monitors for my normal PC use.