GnG board shaky pic

[drbible]

Hi, My original GnG board has a shaky image. It's not too bad and not uniform just random shakes. Gets better/worse randomly. Only other board I have is an original yie ar kung fu and the image is perfect. All on same LCD monitor. Voltage is showing 5v out of power supply and 4.7 at the board.
I'm using a GBS 8200 to convert the image and have tried all the menu selections. The auto button makes the image better to start with but doesn't completely eliminate the shakes. Appreciate this could just be limitations of LCD vs CRT but don't want to open up that debate really.
Just hoping this isn't the pcb.....any ideas appreciated.

 

[Ace`]

The GBS8200 is going to be your problem, there was a setting you can change to improve it but I cannot remember what it was off the top of my head.

Those cheap scalers aren't great, if you want to use an lcd you'd be better off using an lcd tv with a scart input and take direct video from the pcbs.

 

[ColinD]

Wasn't there an issue with these converters if the sync signals are too high a level and you have to attenuate them ? (think someone mentioned this recently)