arcade machine issues

trying to build a custom arcade machine place one jamma board (bottom of the ninth) and the game plays fine place my tekken jamma board in and it comes up split into three portions all upside down and backward can here the game play but nothing moves on screen can take same gameboard and put in my other arcade machine works just fine not sure if i have some ground issues or what but obviously the board is fine just having graphic issues in this other cabinet just not understanding it any help would be greatly appreciated the cabinet has been gutted and i replaced the powersupply with a computer powersupply and the monitor has ben switched out for a twentty inch flat screen and i use a converter for the rgb to vga screen conversion