I'm trying to sort out an occasional sound issue. On certain and specific call outs of my Data East LAH I'm get an obnoxious gargled sound. It's consistent with the same callouts, but only accounts for a small percentage of the game sounds. The rest of the game sounds are fine.

I was planning to order some new ribbon cables and thought I'd check the pin connections first. I noticed on the CN21 a pin (19?) on the far left is missing.

1. Does anyone know what the purpose of this missing pin is? I was thinking it may be the route of my problem, but I've seen a few posts saying that this pin is often missing on Data East machines and is useless. Does anyone know it's purpose?

2. Any idea what else would be causing a few specific call out sounds to come out gargled? I've updated all ROM chips including sound, CPU and display chips to the most recent versions and that did not solve the issue.

Thanks.

CN21_Pin (resized).JPG

Thanks, so I can rule out pin 19. Any other suggestions as to what may be causing the call out sound issue? I'll likely order some new ribbon cables this weekend, but wondering if this has happened with other Data East owners to confirm whether the ribbons are likely the culprit.