Tomorrow my 2nd 1200 arrives.
Oh goodie goodie.
I also made a DIY 1084S-D1 RGB cable, however none of the schematics I found on the net worked for me.
Fortunately I still have the user manual for the 1084S, so fixing/rewiring was easy.
Vertical and horizontal sync is not used only composite sync.
After cutting those (vert/hor) and only use comp sync everything works like a charm.