PC Graphics

[jeffcrass]

I have a custom system with a RX580. I have an old BENQ monitor that works fine when plugged into the HDMI by itself. However, when I plug my new BENQ monitor in via the DP, the HDMI monitor goes blank. It's detected and I can switch to it via Windows Settings, but they won't work at the same time.
Both monitors work fine on their own. No adapters or anything strange. HDMI Out to In and DP Out to In.

[elstaci]

What is the wattage of your PSU in your computer?

when you connect both monitors are there any errors showing in Device Manager?  Do you have the latest BenQ Monitor drivers installed?

Does the Monitor that goes blank say "No Signal" or some other error?

[jeffcrass]

Thank you for your response.
700W PSU

No errors shown in Device Manager.

BenQ Drivers are current. Windows Drivers are current. Radeon Drivers are current.

It does say "No Signal" on the monitor. Blinks that and then goes blank.

[jigzaw]

Maybe a faulty DP to HDMI cable. Had one that failed while on use.

[jeffcrass]

Using HDMI to HDMI on Monitor 2 (Not working)

Using Mini-DP to DP on Monitor 1 (Working)

[fyrel]

With both monitors connected.

Hit WIN+P

What happens when you select each of the 4 options?

[jeffcrass]

PC Screen Only: Monitor 1 Works

Duplicate: Only Monitor 1 Works

Extend: Only Monitor 1 Works

Second Screen Only : Only Monitor 2 Works

That's what has me baffled. Both monitors work fine independently.

[elstaci]

in my opinion sounds like some sort of driver conflict or mis-configured settings.

The RX580 is able to connect, I believe, up to 6 monitors with DP and MST Hub or Daisy DP chained Monitors or a separate Monitor on each of the RX Video outputs.

Have you tried using AMD Eyefinity (Multi-GPU Software) in Radeon Settings to see if you can get both to work at the same time?

[jeffcrass]

That’s what I can’t get figured out. I tried EyeFinity as well. No go. 

I appreciate your input. I’ll keep digging. 

Side note: at one point, I had it working with the HDMI through a hub. Then, after restart, it didn’t work again. 

[elstaci]

one way to rule out a defective RX 580 is by installing it on another computer and see if the same thing occurs. If it does then I would open a Warranty Ticket to find out if your GPU card needs to be RMAed or checked.

You can install a different GPU card and see if it connects with 2 monitors at the same time.

Just thinking what if you disconnect the older BenQ Monitor and connect a different brand Monitor and see if they both work at the same time.  I am thinking that maybe One BenQ monitor is affecting the other BenQ Monitor when they are both connected at the same time.

EDIT: Try connecting your newest BenQ Monitor and your Television set if it has a DP or HDMI input port. See if both work at the same time.

[crossmiles8]

Dude jumping through the different display options actually fixed it for me. Why? I switched to the others like Duplicate and PC Screen Only, and then when I returned to Extend, the red tint on my second display went away.

[jeffcrass · Accepted solution]

I appreciate everyone that tried to help. I had a little bit of an epiphany this morning. After digging through a drawer of cables this morning, I found the DP - DP cable that came with the old monitor (my old computer didn't have DP as an option on the graphics card) and plugged it in. Lo and behold, it immediately started working.
Not sure if this is an issue with my set up or not, but apparently, the DP+HDMI combination wasn't working.

I'm in good shape now. All is right with my setup again.

Again, thanks all for your help.