Have you tried the jamma/vga dips when getting video via the Jamma connector to see if that makes a difference as it may be a toggle that switches between the voltage levels for arcade monitor vs TV (Something like 3volt vs 1volt). There also appear to be RGB adjustment pots on the board next to the jamma edge.
For the sound you may need to change the output to i2s, depending what the card is configured with, standard Analogue I/O I think uses i2s for audio.
For the sound you may need to change the output to i2s, depending what the card is configured with, standard Analogue I/O I think uses i2s for audio.





