Yamaha Motif XS8 Selected Part Control button Not Working

I have with me a Motif XS8 but the challenge am having with it is the “Selected Part Control” button, the “Multi Part Control” button, and the “Assignable 1 & 2” buttons are not working nor shows light.

But when I put the Keyboard on Voice Mode and use the dialer to change the voice, I noticed the green light on the “Selected Part Control” button starts to move from “Tone 1 - Tone 2 - Arp Fx” (the left side of Motif) depending on the voices I selected via the dialer.

But the Assignable 1 & 2 still doesn’t work. Please What can I do?

Since all four of those switches are on the left panel board, and since none of them work, I would look at the transistor array on that board that all of them feed (TA1, which is a TD62381P chip). You can test the switches themselves with a beeping multimeter - just hook it up to the tact switch leads, press the switch, and it should beep. If so, the switch itself works, so the transistor array probably doesn’t.

If you get no beep when pressing the switch, it could be that the four tact switches got damaged, perhaps from a spill or something. They are easy to replace.