This is yet another TV RGB mode using the OSD input.

All this is base on work of Syntax, MarkOZLAD and viletim: https://shmups.system11.org/viewtopic.php?f=6&t=56155

See my blog post for more context: https://hackaday.io/project/170807-darthclouds-retro-gaming-room/log/175650-jvc-av-32920-crt-rgb-mod

I'm using VGA switcher so I need a switch to toggle off the RGB input. If you got SCART use the blanking signal on Ys following the original schematic.

Remove R17, R19, R21 smd resistors under PCB from OSD line.

See service manual jvc_av-32920.pdf.

In RGB the screen will likely be shiftted too much to the left.

Adjust H POSITION in service menu -> Picture -> Option 16