Question Vega 64 displays nothing but a black screen on TV, works fine on monitor

[v1xiii]

Hey all, recently rebuilt my HTPC (new mobo, cpu, ram, and drive) and moved my Vega 64 into it from another PC. Everything works fine on a monitor, but I am getting nothing but a black screen when connected to my receiver or directly to my TV.

Using latest drivers, tested that the HDMI 2.1 cable works fine with it when connected to a monitor. Is set to 1920x1080 60hz currently. Windows is a fresh installation on a new drive.

TV is Sony x900h, Receiver is Denon x1500h. Was working fine previously with a GTX 960. Any ideas?

 

[coercitiv]

In case you're using a CPU with integrated graphics you should check your BIOS settings while using the monitor. I use a Vega 56 on my Samsung Q90T and the BIOS is set to use the dGPU during boot (PEG instead of IGD), but the iGPU is also enabled via the "IGD Multi-Monitor" option (terminology may be different in your BIOS, but description will be the same: enables the iGPU for multi-monitor support). This way you can test with either dGPU or iGPU and see if you get any signal.

If you don't have an iGPU present or enabled then I'm at a loss as to why it wouldn't work, except if you were in a hurry like me and managed to insert the HDMI cable in the motherboard HDMI port, although you would have caught this when testing again on the monitor anyway.