Ok I just figured out the problem. It was 5x mode. Changing it to 4x mode fixed the problem.
I am well aware of the NES and SNES sync issues with the OSSC and certain tv’s due to weird clock rates of each console. I have an SD2SNES Pro with the latest firmware as well as the latest firmware on the OSSC. My other super nintendo which is a non 1 chip plays everything perfectly on my samsung 4k hdr tv. I have had zero synch issues on this tv. When I upgraded to a 1 chip snes for the superior video quality everything still seemed A Ok. No sync issues, video loss, or audio loss. Kirby super star how ever with one exact spot which you can actually trigger your self the video cuts out for a second and keeps doing it unless you move from the spot. It’s a complete black screen if you change the output from generic 4:3 to one of the optimized settings. I was just wondering if anyone else has this specific issue. I took a screen cap of a youtube playthrough of the level in question to show you where it happens. It’s the castle level in Dyna Blade.
My analog sync lpf is on 2.5 and I tried every setting under analog Sync vth and nothing fixed it. No idea what’s going on. Kirby only does it in that one section and it’s not really game breaking right now. Just odd really.
I have been playing that level for a while with a Super Famicom 1-CHIP and so far the only way I can get sync loss there is if I change H-PLL Pre-Coast and H-PLL Post-Coast from their defaults but that should cause issues with all games.
Is your console modded? What RGB cable are you using?
Gonna post this at the top too but I figured out what was wrong. For some asinine reason the 1 chip snes and my ossc has issue with 5x mode in that specific spot on kirby super star. In every other line x mode it’s fine. So i just made 2 profiles. 1 for 4x mode and 2 for 5x mode for literally everything else.