I have a megadrive/32x and snes that work as i get image and sound using a scart but when i try the n64 or ps1 i get only audio using composite cable. I also trieds the snes scart cable but again only got sound.
If you have a multi-adapter (PS2/PS3/Xbox/Xbox 360) plug that has both component and a composite output I’ve found that you can use it to get RGB out of the PS1 by plugging in the composite line in place of the green one on the OSSC, which will give it the sync on green that AV2’s RGsB is trying to find.
I guess if you had a plug that was just the PS1/2/3 that had outputs for component and composite both you could use that as well, it just needs to tap pin 6 on the A/V connector would offer the sync.
Of course he should get a proper RGB cable for it to get the best possible picture, but I was offering it as more of a temporary solution that works. It’s not uncommon to have at least one of those Madcatz-branded squids with rgb/s-video/composite connectors on one end and adapters for Xbox/360 and PS2/PS3 on the other lying around in a big box of old cables.