Oh my... sorry for double posting but I just realized that you have already edited your first post with the solution! I'm a total idiot... :p So, it was DENC-NUS pin 16 that had to be connected to Vcc in order to fully convert PAL to NTSC, right?? (together with an NTSC crystal and pin 7 of the mx83...

I've been interested in PAL/NTSC correct timings (for s-video and composite output on a N64 containing the DENC-NUS) for a while now. After finding your post, I decided to search through my n64 mainboard photos/scans, and I have to say this thread was a lot of help: https://circuit-board.de/forum/in...