Vintage Synth Repair

HI,
I think 1989 is now vintage ! 
if any equipment hasn't been used for several years then it is
"possible" that the battery used to store the preset settings will
either need to be recharged or if its a Lithium type replaced.
the recommended life of some batteries is only about ten years it seems
.
depending on the circuit design of a synth it is possible for a faulty
battery to stop a synth from powering up .
so you might be lucky and find its just a backup battery ....
regards Peter 
South London England