Arp Quadra unresponsive

I finally dug out and powered up my Arp Quadra. All the lights came on and things looked good, but it is unresponsive. It is on program 16. None of the buttons respond to touch, and it makes no sound.
It hasn’t been powered up in many years, but it worked perfectly when it was last put in the case. Any thoughts or suggestions?

thanks!

Randy

Have you replaced the batteries? Look for corrosion.

Thanks, yes I did replace the batteries. Some sign of corrosion on one of the batteries, but none on the board.