@exarkuniv Ok now I feel extremely stupid for not thinking about this before. But because I'm probably not the only one, I figured I'd post this info in case others run into the same thing. After wasting more than half a day trying different HDMI configurations and editing the config file a million times, I realized that by plugging in HDMI 1 into the lcd controller and using HDMI 0 as the output source for a bigger TV, the pi will always check HDMI 0 first for signal and if it doesn't find one, then it goes to HDMI 1. So in other words, no need for an HDMI switch or splitter. Man I feel so stupid but at least the problem is solved now.

@tmoe01 said in Dip Switch help:

Now my task to tackle will be figuring out how to flip the screen for player 2.

this part might involve dipswitches, other clones, or maybe the service menu. look for options to enable cocktail mode, etc.

@tyon2006 said in Using HD LCD with Retropie and RPi4:

Makes sense. Any thoughts on retroarch/emulation station supporting these super high resolutions?

If you add a custom hdmi_mode and it's recognized by the Pi4, it should be used automatically.

On the Pi3, I couldnt even get it to boot up all the way

That's normal, since the Pi3 didn't support these large resolutions.

I did a power cycle/reset on my TV which seems to have fixed the issue. Im guessing my TV may have done an automatic update overnight which may have caused the issue in the first place.