Quoted from embryonjohn:I’m trying to install a new Alltek MPU in a 79 Stern Magic. Everything plugged in as one would expect but the 2 top ribbon cables go to 32 pins (J2) on the original board, the new board has 34 pins. The game boots with the last two pins exposed but it makes an awful sound. Are there any modifications needed when installing these board into early Sterns as opposed to Bally’s
Only pin one to 32 are used on both mpu and sound board (including later sb300 sound board). Make sure pin 1 goes to pin 1, pin 17 to pin 17 etc on both boards. Pin one is to the right as you look at both boards mounted in the head.
Common for this ribbon cable to be damaged. It rips at the ends pretty easily.