[SOLVED] Monitors flash black randomly when graphics card is connected to HDMI, but not displayport

[Colbybrunner]

I have a 1080ti in my build, and it's worked fine for the past few years. In my pc setup, I have 3 monitors and a tv all connected to the GPU.

I changed a setting in my bios a few months ago to allow both onboard graphics and GPU at the same time. I recently turned this setting off, as well as downloaded oracle virtual box. These are the only changes I've made. I noticed that at random times, all my displays will turn to black for a second or two and then go back to the image like nothing happened.

I tried turning the bios setting back on, running my pc without virtual box on, and using a completely separate tv, hdmi, and power cable elsewhere in my house.

While connected to just the second tv, I noticed while playing games, that it flashes frequently while connected to either of the two hdmi ports on the graphics card. However when I use the display port connection with a DP to HDMI adapter, the flashing doesn't happen.

I have no idea what could be causing just the two hdmi ports to act up, but nothing else.

 

[Colbybrunner]

Update: it looks like it does happen on DP too, just a lot less often and the screen is black for a much shorter time.

 

[Obiwancanabi]

id try deleting any video drivers and do a fresh install, it could be hardware but its more likely software. I used to have problems at certain resolutions, changing some of the settings (resolution, hertz) can help, How are your power settings? if you are set to some power saving profile it might not kick out enough volts for the tv and pc to see eachother, both send out a couple of volts so they know when they are connected, sounds like you are getting brief drop outs on that voltage, if ur HDMI cables are too long it can do the same effect, could be worth re seating the GPU to make sure all of the contacts are right, but if all that fails im pretty stumped.

 

[Colbybrunner]

I completely uninstalled my graphics card display driver and reinstalled the latest 1080ti drivers from the nvidea website. I thought it worked at first, but it quickly started happening again. It now happens on the display port ports and the hdmi ports, almost every 3-5 minutes. The hdmi cables I'm using aren't super long. There shouldn't be much signal loss with them and this has never been an issue before

 

[Save me from my PC]

I completely uninstalled my graphics card display driver and reinstalled the latest 1080ti drivers from the nvidea website. I thought it worked at first, but it quickly started happening again. It now happens on the display port ports and the hdmi ports, almost every 3-5 minutes. The hdmi cables I'm using aren't super long. There shouldn't be much signal loss with them and this has never been an issue before

please..... please tell me you found a solution. ive been on this for WEEKS.

 

[Colbybrunner]

please..... please tell me you found a solution. ive been on this for WEEKS.

I think I understand what the issue is. I've tried so many different solutions and configurations within Nvidia Control Panel and Windows display settings.

In my search, I was somehow able to make all of my 3 displays stop flashing black, but every 15-20 minutes or so, the screens would lag for a second, and readjust which applications were on which monitors. Still basically the same issue, but not as bad.

I tried a test by completely disconnecting my TV HDMI from my PC and the issue completely goes away. No flickering at all on the remainder of my three monitors.

This allowed me to narrow my search down for troubleshooting. About a month or so before this started happening, I had replaced the 47 in. 1080 TV in my bedroom with a 75 in. 4K Samsung TV. I had previously used this TV in my living room with this same PC for VR and not had any issues.

While researching flickering only when connected to a 4K TV, I saw lots of posts about the colour profile from Nvidia Control Panel. I tried playing with these settings and changed my monitors and TV to "Output color format: YCbCr444" instead of RGB. This somehow made my situation worse and the screens went back to flashing black.

Then I remembered an issue I had had when this TV was in my living room and connected to my Philips Hue Sync Box. The light sync and displays kept going black every 20 minutes or so.

I had done extensive research on that issue, and fixed it by going to the settings on the TV and turning off the UHD setting for the display.

When I brought my TV in to my bedroom, I had plugged it in to a different HDMI port, and it just happened to be the second port where I hadn't bothered to turn off the UHD setting.

I turned UHD off for both ports, and it seemed to fix the issue for a while.

Today, I noticed that the screens were still flashing pretty badly, but I'm fairly convinced it has to do with UHD on the TV because it's the exact same issue I had with the Sync Box, and had just forgotten about.

I realized that part of the issue may be that I am using a pretty generic HDMI cable I got off Amazon. It's possible that UHD causes issues because the cable isn't able to support the signal all the way through, and it's a slow cable compared to some of the others.

I bought a 10 ft 8K capable shielded HDMI cable off Amazon today and plan to replace it once it arrives. I am fairly confident this will resolve the issue.

I'll update back here when I install it to let you know if that resolved the issue, but hopefully I've given you somewhere else to start looking.

 

[Colbybrunner]

I tried everything. I could not get the flickering to stop. The 8K cable did not prevent the flickering.

I opened this thread on the Nvidia forums that details a few more steps I took:

https://www.nvidia.com/en-us/geforce/forums/user/754964/430036/3-monitors-flicker-every-20-minutes-when-4k-samsun/

It seemed like something on the TV was sending a handshake to my PC every 20 minutes or so and causing it to freeze up/flicker for a few seconds.

I was able to determine that something was happening with the TV when I left Discord open one day. I noticed that every time the screen would freeze/flicker, Discord would pop up saying that a new Audio Device had been detected, and listed my TV as the new device.

I changed every setting on the TV. I played around with game mode, UHD, judder, setting everything manually, but nothing stopped the flickering.

Then, out of desperation, I went to the settings on the TV and just completely reset it back to factory settings.

I'm not sure what changed, but resetting the TV completely took away the flickering and screen freezing, and I haven't had the issue for over a week. I spend all day working on the computer, so I would have definitely seen it by now.

I have been playing around with the different settings on the TV again, and if I find out which one causes the flickering, I will update this thread.

Hope this helps!

 

[Colbybrunner]

I believe I was able to resolve this issue. There is a combination of things that work, and you may have to modify the steps for you.

The first step is to turn off UHD in your TV settings. I only use Samsung TVs, but it is either called HDMI UHD or Input Signal Plus. For some reason, this setting causes constant flickering. Something I noticed on the Samsung TV is that, even if you turn Input Signal Plus off, if you have "Game Mode" turned on or set to "Auto", it will automatically enable Input Signal Plus periodically and cause the flickering to return.

I turned off Game Mode and Input Signal Plus, and the flickering went away.

Another setting that you can mess around with is in the NVIDIA Control Panel, and allows it to work even if Input Signal Plus is turned on.

Open NVIDIA Control Panel > Display > Change Resolution > Choose your TV > Scroll down to "Apply the following settings" > "Use NVIDIA color settings" > change "Output color format" from "RGB" to "YCbCr422"

This color format appears to reduce bandwidth and also eliminates flickering. The only issue is that this setting seems to occasionally reset itself and cause the flickering to return.

Hope this helps!