I'm facing some frustrating problems with the HDMI outputs on my TUF-RTX4090-O24G-GAMING graphics card. I've tested three different monitors: a Samsung Syncmaster 2032BW, an AOC 24G2SPU, and an LG 27GX700A-B, and I'm running into two main issues. First, the HDMI hot plug just doesn't work. When I connect a monitor to the HDMI port while my PC is on, there's no output signal, and the monitor isn't detected until I restart my system. This works fine on other PCs. Second, while trying to boot up games like Cyberpunk 2077 on the 27GX700A-B, the HDMI signal cuts off completely whenever the framerate goes beyond its variable refresh rate window, making the monitor undetectable until I reboot again. DisplayPort works without any issues, allowing me to reconnect anytime without losing the signal. I've already updated the VBIOS, reinstalled the latest drivers, and even tested the card with different PCs and setups including an iGPU and Intel graphics laptop. ASUS has been contacted about an RMA, but I'd love to know if there's anything else I can try before shipping the card off.
4 Answers
It sounds like you’re hot-plugging your monitors quite a bit, which might be damaging the card’s connectors. You could consider using short male-female crossover cables to minimize any wear and tear. Just a thought!
It could be that the clock rate of the 27GX700A-B is causing the HDMI signal to drop. Some monitors can get overclocked, so make sure to check your refresh rate settings! Also, check if there's any firmware you need to update for your monitor.
The 27GX700A-B runs at 280Hz by default and doesn’t have available firmware right now, but I think a Windows driver is needed to enable VRR support. The Samsung runs at 60Hz, and the AOC can go up to 165Hz but defaults to 60 unless I change it.
Have you thought about trying the graphics card in another PC to see if the problem persists there? It could help narrow down whether it’s the card or something else in your setup.
Make sure your HDMI cable is in good shape too! Sometimes faulty cables can cause issues like these. Have you tried a different HDMI cable just to rule that out?

Actually, I don't hot-plug often; my last monitor was plugged in for a year without being unplugged until recently.