I dusted off and read the manual, and it suggested battery replacement after 5 years
! So last night I went downstairs and fired up the D50. After close to 20 years all's well
I looked around and found a Musitronics box with some cards in it, specifically a ROM card of the original voices and an EPROM card(with different voices) that I apparently bought at the time.
I'm going to take all the voices that I really like off the EPROM card and stick them in the D50. Lots of original, silly internal voices there to overwrite. After saving all
internal patches back to the EPROM card, only then will I do the battery swap thing.
I really took the time to create some killer B3 voices, and occasionally still use them. Still a great old board. BTW, thanks for the additional battery info.