sync problem with mega drive and sony pvm 20 L4

I recently bought this pvm monitor and is fantastic, everything looks perfect on it, but I have a sync issue with the mega drive, only when picture is totally white or bright.

I usually use a cable who takes sync from composite and got 3 75 ohm resistors on the r,g,b lines.

I tried get sync from the c-sync pin without internal modification (no image at all), then gettin it from pin 11 of the cxa adding 75 ohm and 220 uf: great result on my fd trinitron but distorted and blurry image on the pvm (and commodore monitors)

then i got back to composite video as sync, adding 3 220 uf caps to the 75 ohm resistor on the r,g,b lines but image is a mess on every monitor...this is strange cos I found this scheme on many sites...

what should I do?

I can't think there is not a way to get proper mega drive sync on the pvm

 

Use an LM1881 to strip the sync.

Why have you put 75 ohm resistors on the RGB lines? Just measure the output and balance if necessary. Try it without to start, even.

 

What Commodore monitor?
I have a 1084s which has no problems using the composite video as sync... however, I don't think I have any/many games that display a black/white image for very long...

I had issues with those stupid GBS video converter boards not syncing with Sonic 2, when playing 2 player, as I believe the megadrive runs at a different resolution when in 2 player mode....

 

the sync problem on white screens is with the sony pvm, not with the commodore monitor which is fine

I use 75 ohm in rgb lines cos without image is too bright, i tried alsi without the resistors but won't sync anyway

 

actually the c-sync is the right way, I put resistor and capacitor in the wrong order so I got no result....

the correct line is pin 11 of cxa - 75 ohm - + 220 uf - - sync output

I did a lot of experimentin using the ext port as output with stereo audio and puttin a switch between video composite and c-sync...nice! but unfortunately I have no d-sub plugs that fit the ext port, so probably I'll do the same with the 8 din port