No signal coming from GPU

[Hero7750]

I'm having a problem were I get no signal coming through the GPU on my second rig, on the IGPU displays anything. The graphics card does work and it is happening on two GPUs I've tried (both r9 390s). This is a problem that has been happening on two motherboards (a Dell brand motherboard and an MSI z77-g43). No matter what pcie slot I try the same thing happens, no image coming from the GPU, only IGPU. This has also happened on two different processors (i5 2400 & i5 2320) and in both configurations in either motherboard. I know it's not the power supply because I tested it in my main rig and it works fine. The GPUs fans do start spinning so I know it turns on. I've looked up this problem and people say disable the IGPU in BIOS but I can't find any settings for that (if anyone with a similar motherboard can help me find that option if there is one). Any help will be appreciated!

 

Recap:
-No GPU signal coming from two different GPUs 
-GPUS are known working in main rig
-Happenig on two different CPUs and two different motherboards

[Natsoup]

If you try each of  them alone, any luck?

[Hero7750]

Just now, Natsoup said:

If you try each of  them alone, any luck?

What do you mean by that? Try each gpu individually? Yes I have, no luck.

[DexterSmythe]

If you have a dGPU installed the iGPU will not be able to do anything.

 

Have you tried turning it off and turning it back on again?

[cpuwaiy]

I had this with a gtx 950 and z77. I had to change one of the video slot bios settings to legacy.

[GonzoPoet]

I had a similar thing when I purchased a new monitor. The default input for the monitor was HDMI and I had to manually change this to DP on the monitor. Hope that helps.

[Hero7750]

4 minutes ago, CapedCrusader21 said:

If you have a dGPU installed the iGPU will not be able to do anything.

 

Have you tried turning it off and turning it back on again?

Well obviously that isn't the case because the dGPU isn't working.

[Hero7750]

2 minutes ago, GonzoPoet said:

I had a similar thing when I purchased a new monitor. The default input for the monitor was HDMI and I had to manually change this to DP on the monitor. Hope that helps.

If that was the problem then I still shouldn't be getting signal from just the igpu