A monophonic reworking of the Jupiter 4 basically with some added goodies.
Anyone? Lots of similarities to JP4 obviously so cleaning issues on key switches (carefully scaling with an appropriate dental pic, etc. is often one way to remove tough residues).
Roland still stocks many parts for older instruments! You can always order them through your local Service Center and see what happens! Otherwise I have some parts also so don't hesitate to ask.
Contact Sound Doctorin'