Have an Alpha Juno One which I originally bought in 1985. Has not had much use. Just cleaned the key contacts because some keys were not playing. Reassembled, but some keys still not working. If I switch the instrument patch, say from elec piano to violins, keys that did not play start playing again, but a different set of keys stop! Weird..usually the keys are a tritone apart, like all the Es and all the B flats. If I change to another instrument, the Es and B flats work, but the C s and the F#s are all not working.
I did not touch the battery, and have never changed it. The keyboard has been sitting in storage for about 12 years.
Can you help?