Is it an early model system? I've had this issue with an early system on a consumer TV. Replacing some of the (incorrect) caps/resistors in the video circuit helped, but didn't fix the issue. I ended up trading that one and getting a newer revision system.
Yeah. I my case, I intentionally bought one near 20k serial so that it would be in the range considered to have the best RGB output. Nobody mentioned issues with BVM/PVM sync.
I just recapped it today (partial) to replace the caps and resistors with the new “revised” values that are now standard for the NEO-AES board cap kit from console5. Sadly, my experience is the same as a poster above in that it didn’t make any difference with the slant at the top of the screen for me.
This board has what looks like lots of factory performed mods. Strange cables and components randomly soldered together and a daughter card with ICs. I’m not surprised that something is off with the sync.
Next step for me is to try some sync cleaning using a combo of gscartsw and an Extron. Have both now but need some cables to make it work. Failing that, will just have to decide how important it is to be able to play on my CRT. It isn’t what I’d call a great play experience for most games. It does this both with RGB and Composite on this monitor.
-sphiend