Korg Polysix
Another analogue synthesizer (which I don’t like) arrived in my workshop. This was supposed to be a straightforward repair – replacing the infamous rechargeable battery that backs up the RAM memory. Over time, these batteries deteriorate, leaking electrolyte onto the circuit board and causing extensive damage.
It turned out that this battery had already been replaced once with a new one of the same type, after the previous one had caused the damage described above, which had only been partially repaired. Unfortunately, several PCB traces required further repair, a number of vias had to be bridged with wire links, and the entire circuit board needed thorough cleaning. Finally, a CR2032 battery holder was soldered in place and fitted with a new coin cell battery.
The infamous SPARK KILLER capacitor also required attention. It had already started to leak, had become swollen, and would likely have become a fire hazard in the near future. In addition, the instrument could switch itself on whenever the power cable was connected, regardless of the position of the power switch. Likewise, once powered on, it would not respond to the switch and remained powered. The capacitor became hot, emitted a burning smell, and required immediate replacement.
As a result, what was meant to be a simple battery replacement turned into a much more complex repair.
