HELP! Roland Juno-6 repair advice!!

[kylzrnr]

Working on a Roland Juno-6 for some repair practice. The thing is in pretty bad shape cosmetically and just sits in my friend's practice space.

It powers on, the LEDs light, but produces no sound at all when running through either of the audio out jacks. When I try the headphones jack, it produces a constant high-pitched note that changes to one other note, when any key is pressed (no matter which it is). Tried pressing all the switches on and off, and moving the sliders to see if it was coming from one of the electromechanical components, but still nothing different.

I took it apart and found no visible burns or damage, but did find a few minute solder joint issues on the CPU board. Nothing that seems all that crucial, though.

Anybody ever experience any thing like this? Any specific parts that I should check or try to replace before resoldering these tiny joints? Really any advice or feedback is welcome.

Thanks!

[synthparts]

The first thing I would check is to verify all the power supply voltages are within spec and getting to the voice board, have you done that?

[kylzrnr]

Sorry for the delay, forgot I posted this here.
Yes, I checked the voltages. They are within spec and getting to the voice board.