Computer won't POST with monitor switched on

[justin_sap]

Hi, I recently built my PC and had a cheap Kogan branded 1080p monitor connected to my Radeon 290 Graphics card via DVI and everything was all good.

Then I recently upgraded the monitor to a 1440p Samsung and it's connected to the GPU via Displayport cable.

It's very strange that if I restart or shutdown my PC, when I boot it, it doesn't POST as there is no beep or anything, no display etc. just lights and fans running etc.

If I turn the monitor off via the switch at the back and boot the PC, it will POST as I will hear the single beep and at that point I can switch the monitor on and it will display as normal.

I'm thinking it's an issue between the Monitor and GPU but I don't know what it is and it's very annoying. I don't have any known issues with my 290, everything functions normally and have the latest drivers.

Also I've tried changing settings on the monitor such as the input changed to Manual instead of Auto and PC and TV Mode etc. Nothing fixes it. I can't find anything on Google relating to this issue.

Anyone have any ideas or know what the issue may be?

Thanks.

 

[N3rdR4ge]

Have you tried a different signal such as HDMI or dvi? Also, have you tried a different display port wire? Rule that out first. Next try the monitor on a different computer. If those two are ruled out the answer to your problem lies in your GPU.

 

[justin_sap]

Have you tried a different signal such as HDMI or dvi? Also, have you tried a different display port wire? Rule that out first. Next try the monitor on a different computer. If those two are ruled out the answer to your problem lyes in your GPU.

Hi, I tried a HDMI I had but I think it's old as it didn't support 1440p resolution. I don't have much money to just buy another cable but I guess I have to. I'm sure it's not the Displayport cable I bought as there is no issue with the actual signal. Logically, I'm 99% sure it's a compatibility issue with the GPU and BIOS using the Displayport but I can't just swap out my GPU because of the annoying problem as my computer, monitor and GPU all work fine.

 

[N3rdR4ge]

Sounds like you are on the right track to figuring it out. It is a very strange problem. Best thing is to just keep ruling things out.

 

[MagicPants]

I had the same issue, I just bought an asus mg279q display and it would cause my system with an 290x to hang on every reboot if the monitor was turned on. At first I thought it might be the power over dp issue with pin 20, but my cable (from accell) was certified to not have that issue.

Anyway, when I turned off fastboot in my mobo's bios the problem went away. (and I can't tell any difference in boot speed.)