On 02/25/2017 09:28 AM, N_Cook wrote:
Stored indoors for some years and then powering up, missing notes and
some top panel sw functions missing.
full sm here
http://www.synfo.nl/servicemanuals/R...VICE_NOTES.pdf
same 2 notes ,not each octave , but as keyboard is scanned as 8x8 matrix
keys 8n and 8n-2 are missing , n= 1 to 8.
Hopefully that means the 74LS138 3 to 8 demultiplexer did not survive
1/3 century,internal metalisation creep or something, rather than main
micro problem.

Did you try doing a factory configuration reset? These old Rolands use a
battery backed SRAM to store both patch data and for the system
scratchpad RAM, if it gets corrupted you can get all sorts of problems
like the ones you describe.