I had the same problem years ago when I owned a DX7. I opened it and did a re-flow of every solder joint I could find on the keyboard PCB. It worked like a charm and never misbehaved after that.

What a beautiful piece, Push-Pull! It reminds me of Vangelis' Soil Festivities work a lot. I still come back to your earlier From Io to Callisto Jupiter 6 track.

Everyone knows DX7 can do great EPs, organs, wooden and metal tuned percussion, plucked sounds, etc, This is not entirely true, there are many people who wonder what the DX7 is. I'm sure you know the DX7 is great for these kinds of sounds but even in this category there are many surprises, let alon...

These sounds are great, even though they show only a small part of the DX7's sound palette. "Ultimate" is a bit misleading in this context.