I just picked up an Ikegami TM20-9RPC (similar to a TM20-9H but with a PAL decoder). I've got a decent working knowledge of video, but I'm pretty new to CRT PVMs.

It's working with composite video input, but missing terminators (I've ordered a set, waiting on delivery). It seems to have been calibrated without them though.

The monitor has an RGBS input on the back, but no obvious way to select it. The Video Select A, B, and C buttons on the front seem to relate to the A, B and C composite inputs (though B doesn't work, I wonder if that's a clue or just a fault). I also tried playing with the switch bank a bit (none of them active, A+B active, A+C active, all of them active) but that doesn't do anything. Selecting external sync doesn't make it work either, nor do any of the other controls.

I've tried connecting both a PSX and a Playstation 2 with a home-made AV+component cable, using the composite video output for sync. Both work with the composite input but not RGBS. I'm also waiting on the delivery of a similar manufactured cable in case I messed something up, but I feel like I'd have to have fucked up quite badly for RGBS to not at least partially work given the composite/sync line works.

Anyone have any ideas? 

Ikegami TM20-9RPC - Has RGBS input but no obvious way to select it