SCART cabling - Where did I go wrong? (Wondermega RG-M1)

[DejahThoris]

Okay, so my internal modwork seems to be fine. Checked with a multi-meter from each pin of the Sony IC / S-Video plug (for sync) to the MIDI port pins, everything is great.

https://www.gamesx.com/grafx/wondermega.jpg

I took an old Megadrive 1 SCART cable, removed and desoldered all the wires on the DIN, and resoldered them to the appropriate spots on the MIDI connector.

R/G/B are R/G/B colored respectively.
Yellow is Sync.
Brown is ground. (I've also tried Black as ground, but no love).

My OSSC just says "No sync".

I'm at a loss. I've double checked that my soldering in the cable is proper as I get continuity from the wire in the cable to the Sony IC pins. I've also double and triple checked my pinout to the MIDI port. What I am not entirely clear on is which ground pin I should be using on the SCART side, and if any of my wires are in the wrong place, as I've seen a bunch of different SCART pinouts on the web, and each has a bunch of different grounds.

My SCART cable-end:
https://imgur.com/a/heBpu

Any ideas/advice would be great.



UPDATE:

I knew soon as I posted here I'd figure it out.

So I put both brown and black on the ground pin, and now it works fine.