Mike Chi has recently released a new firmware for the RetroTINK 5x, with two changes. The first is an adjustment to the composite video encoder that helps prevent the “curling” on the upper part of the screen that can sometimes occur with NES / Famicom games. The next is an option in the HDMI menu that sends a flag telling your TV to enable “Freesync” Variable Refresh Rate (VRR), if it’s supported. While this isn’t quite true VRR, it should be a help for compatibility with many displays. Here’s links, with more info below:
Purchase the RetroTINK 5x here: https://www.retrotink.com/product-page/5x-pro
Download the latest RT5x firmware here: https://www.retrotink.com/post/retrotink-5x-pro-firmware-updates
Update RetroTINK: https://www.retrorgb.com/how-to-update-your-retrotinks-firmware.html
Update RetroTINK Mac: https://www.retrorgb.com/update-retrotink-products-on-mac-linux.html
The VRR flag is an interesting option, as it seems to increase compatibility with certain consoles without switching to triple buffer mode. My guess is simply setting the flag to tell your TV there isn’t a standard 60Hz signal being sent, might be all this needed, however at the moment I don’t have the ability to test if the RT5x’s HDMI transmitter chip will actually allow variable refresh rates to pass through without resetting the mode (like when resolutions change).
Either way, it’s a free update that you can toggle with no risk: If it helps, cool. If not, it won’t take anything away from the product, so I’d say just update to the latest firmware and see what happens!