willemdrijver wrote:My ACER monitor tells me that it detects 1280x720 with H-Freq=37Khz and V-Freq=50Hz.
Assuming 37 is rounded down from 37.5 those are the correct timings for plain old vanilla 720P50. It could be an RGB 8 bit 4:4:4 vs YCrCb 10 bit 4:2:2 issue but the US4k should be cool with either. More likely just basic incompatibility somewhere. Is 720P60 an option?
Sometimes an active split can stabilize the signal and there's always the option of converting to SDI, that process should cost
only time and money, leaving the original pixels intact.
When the price of the Atari 1010 Cassette drive dropped to $200 dollars I forked out my own money to pimp my 1200XL. Cload, then a solid hour of raspberries, then (hopefully) Telengard.
Good Luck