Question DELL Monitor picky about detecting input (Not displaying input)

[username-s]

This is split from another question I asked here on this post.

To summarize, I have a Dell monitor that is very picky about detecting input sources. Looking back, I've had this problem for as long as I remember, when I used to have trouble connecting my macbook to it as an external display, but I thought it was an issue with the adapter I used to connect HDMI. Now however, I notice it even more after getting a PC and not being able to display anything.

Some important Specs:
- Monitor: Dell 2721HGF (144Hz Monitor)
- Motherboard: MSI B250 PC Mate
- Processor: Intel i7 6700
- GPU: MSI Nvidia GTX 1050 2G/Sapphire Nitro AMD Radeon RX 580 8G

I got a used PC that had a GTX 1050 and I was able to boot it up just fine. However, the monitor wasn't able to detect the integrated graphics, which initially I thought was because the processor had no iGPU or something. It didn't bother me since I tested using the 1050 anyway and upgraded to an RX580 shortly after. I had trouble at first trying to set up the RX580 because nothing displayed either, which I worked around by connecting both the 1050 and RX580 and installing the AMD drivers while the HDMI was connected to the 1050.

Thought it was a GPU issue that I wasn't able to boot into BIOS (boot straight to windows), but after days of troubleshooting, it turned out the monitor was the problem. I was able to access BIOS and the boot menu when I connected the HDMI to an small 60Hz TV I had lying around. I was also able to access BIOS and use the iGPU as long as I first boot into either one connected to the TV, and then switch it to the monitor after. This is pissing me off because the only way for me to say dual boot to Linux is for me to connect to the TV first, and then switch the display the monitor once I've left the boot menu. But every single time I spam the BIOS button, the monitor doesn't detect a display and just immediately goes to standby without a countdown.

I'm so lost. Is there some way to troubleshoot the monitor itself? It doesn't look like there's alot possible to do after looking through the manuals and everything.

 

[Lutfij]

I think you should connect the display with another cable(one that hasn't been used as of yet) courtesy of a donor system sans the GPU's you have at hand, to rule out a corrupt VBIOS or faulty ports on your old GPU's.

BIOS version for your motherboard?

I would suggest using DDU to scrub your entire platform off of GPU drivers,(intel, Nvidia and AMD), then manually reinstalling with the latest driver from AMD's support site, in an elevated command, i.e, Right click installer>Run as Administrator.

What is the make and model of your PSU and it's age?

 

[username-s]

I think you should connect the display with another cable(one that hasn't been used as of yet) courtesy of a donor system sans the GPU's you have at hand, to rule out a corrupt VBIOS or faulty ports on your old GPU's.

BIOS version for your motherboard?

I would suggest using DDU to scrub your entire platform off of GPU drivers,(intel, Nvidia and AMD), then manually reinstalling with the latest driver from AMD's support site, in an elevated command, i.e, Right click installer>Run as Administrator.

What is the make and model of your PSU and it's age?

On the post I linked on the OP, I made sure to flash GPUs VBIOS and update the BIOS version of the motherboard.

Not sure how old the PSU is to be honest as I got it used along with the motherboard, but its an EVGA 500 BR

I cleared all the drivers with DDU, in fact it was a clean install of windows to begin with and I was only able to boot into anything with the 1050 card plugged in, not even the iGPU

 

[username-s]

On the post I linked on the OP, I made sure to flash GPUs VBIOS and update the BIOS version of the motherboard.

Not sure how old the PSU is to be honest as I got it used along with the motherboard, but its an EVGA 500 BR

Literally the only workaround I found is connecting to a second monitor, where the POST screen would show up and let me dual-boot. Otherwise, no luck.

I got in touch with Dell support, but they keep gaslighting me into thinking my PC is the problem. I am not experiencing this issue with any other monitor and I've tested my PC with 4 different monitors