I'm still scratching my head here like.
The vga scaler has the RGBs connector,and the pins are Vss(gnd) Vss(gnd) vsync hsync sync B G R .And people are having problems with the lm1881 and their console's rgb with cvideo ?
why are you using vsync from the lm1881 ,it's not needed ,it's not even a good enough vsync (but there is a more expensive IC which gives out a proper vsync ),just the csync is needed to be connected to sync(S) pin on the 8 pin RGBs connector ,as hsync and sync are sharing the same line ,just check continuity (and it's the same for the other 5 pin rgb Vss(gnd) sync connector,it's sync is connected/common .
The only console that wouldn't work with this set up was my PAL I psone(i'm also using the dirt cheap DIY SLG that's on gamesX).Within 15 mins i had fixed the psone and the black NO SIGNAL screen .
My set up is this
A 3 port selectable scart switcher,which has the lm1881 inside and it's powered by pin 8 of each console's scart pin ,easy.This then goes through a female scart to the 8 pin connector on the scaler (using just RGB ,csync(labled S on the scaler pcb) , Vcc/gnd of the included harness) .My DIY SLG is on my solderless breadboard and connected to the underside hsync/vsync/R/G/B points of the middle vga out socket .Power is supplied to the DIY SLG via the included ,two pin power harness (temp for testing ) and this goes to my cheap lcd at 640*480 and looks bloody good ,even more so on my cabs cheapo chungwah vg monitor
All is bloody good ,jp mega drive ,cmvs,ps2 ,psone,ps 1 ,jp white saturn.
Now i have modded the scaler again.It's got an 8 pin mini din(input) and a stereo out socket .I'll chop off the scart plug that comes from the multi scart selector,stick on a 8 pin mini din plug and that's that .