Weird HDMI Motherboard Issue

jwilliamson47 · 6 Apr 2018 at 17:21

Hi all,

Just finished building my new Z370 system and the only thing which is acting weird is the motherboard's HDMI port. When plugging in the cable it's all fine and posts a perfect image. However, the screen flashes black every so often. It's quite random and doesn't seem to be a result of CPU or GPU loads. Also, it tends to happen rarely. Please note, I'm connecting to an ultrawide 3440x1440 monitor.

I think the issue has stopped when dropping the resolution down to 2560x1080.

Do you think the HDMI port has a fault, or could be a software/monitor issue not liking the 3440x1440 resolution at 30Hz?

orbitalwalsh · 6 Apr 2018 at 19:51

Plugging in HDMi cable into Mobo when you have a GPU ?
Have you not tried just GPU or Mobo only with selected default Graphic/display option as iGPU

jwilliamson47 · 6 Apr 2018 at 21:18

orbitalwalsh said:
Plugging in HDMi cable into Mobo when you have a GPU ?
Have you not tried just GPU or Mobo only with selected default Graphic/display option as iGPU

Not tried the GPU via HDMI as I'll be using the DisplayPort which worked fine. It's not a huge issue as I'll be using a discrete card, just a bit odd.Other iGPU like the DVI worked.

mrbazmondo · 7 Apr 2018 at 01:36

If you're going to continue using it I'd look in the BIOS and up the amount of main memory assigned to the iGPU to see if that fixes it.

Do you have just the one monitor or were you planning on running a 2nd off the iGPU. Personally I'd run both off the PCIe GPU.

jwilliamson47 · 7 Apr 2018 at 01:51

mrbazmondo said:
If you're going to continue using it I'd look in the BIOS and up the amount of main memory assigned to the iGPU to see if that fixes it.

Do you have just the one monitor or were you planning on running a 2nd off the iGPU. Personally I'd run both off the PCIe GPU.

I just have the one monitor and will use a 1080Ti powering 3440x1440 via DisplayPort. Noticed the HDMI issue just testing a new motherboard. So it's not a big deal as won't be used. Just a strange problem.