Korg Poly 61 suddenly freezes on power up

Turned on the Poly 61 this morning and no sound, no read-out in program/parameter indicator; leds are stuck on for program, parameter, write and hold buttons. I’ve was happily playing this instrument last night; no thunderstorms, all the other synths connected to the same power are working fine. I didn’t see any troubleshooting section in the manual. Any ideas?

Some thing to check:

  1. Fuses on the power supply board.
  2. If your comfortable with a meter check the voltages on the power supply (CN24A connector)
    Should be +15, -15 and +5VDC.
  3. Check the on-board battery on the main board for leakage. The battery acid will corrode the copper traces on the main board affecting operation.
  4. Capacitors on the power supply should be changed due to their age.

Hope this helps.

Thanks, I “fixed” it by opening it up and closing it again. I’ll open it up again and follow these suggestions

Definitely check for battery leakage - that can make a huge mess of the circuit board. If it’s just starting to leak, fix it now before it spreads. I think the battery is more prone to leak after sitting unused for many months.