rgb mod on pc engine cdrom2 doesn't seem to work with gscart

[8bitForLife]

ok I have a cdrom2 modded for rgb. works fine if I plug straight into scart2comp but if I use a gscartsw and a scart to scart it doesn't work.

the mod inquestion was from
https://www.otakus-store.net/en/content ... -Duo-Duo-r

link no longer works.

Could someone please chime in on a possible fix or do I need to redo the rgb mod with another one. if I have to go that route then my cables are worthless.

maybe superg might know.

[Kez]

The gscartsw detects sync in order to switch inputs. That mod you linked (here it is on archive.org) takes csync from the HuC6260 which I believe is not a properly specced c-sync signal. I would guess it is not able to trigger the gscartsw.

You could try adding a buffer circuit to the csync line, or instead of csync using the composite video signal.

[nam9]

Have you tried plugging the PCE into scart 1 on the gscart?
That may allow it to be detected.
Alternatively you may want to redo your RGB mod with the Voultar IFU RGB mod.