via this auction

In addition to fixing any problems, we rebuilt the power supply, replacing capacitors, bridge diode, resoldering connections, adjusted voltage. Removed keyboard, removed and cleaned bus bars. Cleaned key contacts. Cleaned up front panel, knobs, resoldered bender board, cleaned and lubed all pots and switches, replaced caps on ADSR, VCF, VCO, ring mod and LFO boards. Resoldered connections. Replaced power cable. Cleaned tolex. Fixed a problem that was present when it was new - back panel VCO control didn't work because it wasn't wired up (someone must have been sleeping at the Roland factory), replaced terminal for molex connector #12. Replaced power line terminals. Recalibrated. Tested systematically and completely multiple times and working perfectly.
SN 52133x