Question PC works fine on my monitor, but not on TV

[Brummieblue]

Hi folks, my kid is running a fairly new (2nd hand GPU), although not top-notch pc. He uses HDMI to his TV, which used to work, but it stopped showing on screen, although it does boot. He brought it round to mine for me to check, and I hooked it to my monitor, and it came on instantly. Using his leads etc. He runs his Switch through the same HDMI channels, which works.
He took it home, nothing. He's just tried it again, at his, on a new TV, with a different lead, and still nothing but a blank screen. Any ideas please folks?
His PC consists of, roughly,
RX 470 8gb , ryzen 5 2600 and 16gb crucial ram 2x8gb
mobo asus prime b450 plus (or similar).
Win 10, nothing special otherwise.

He is 100% running from his GPU, it wasn't plugged into the part of the APU/CPU system

 

[Lutfij]

Welcome to the forums, newcomer!

Make and model of his PC's PSU? How old is the unit in the build? Also, can you check and see what the OS version(not edition) is? BIOS version for the motherboard? I'd try and use DDU to uninstall the GPU drivers, reboot then manually reinstall the GPU driver in an elevated command, i.e, Right click installer>Run as Administrator.

The processor on his build doesn't have an iGPU so he won't get anything anyway when plugged to the motherboard's display outputs. Can you ask him to swap cables to the TV? Make and model of his panels(TV/Monitor)?