Korg T2
This repair, although typical, was a bit different from the others. As usual for instruments from this era, the electrolytic capacitors in the audio path had to be replaced, because the output signal level was low and distorted. That part was nothing new. What was unusual were the components themselves. In this Korg model, bipolar (non-polarized) electrolytic capacitors were used in the audio path. This is due to the design: there is no virtual ground, only a fully balanced circuit. In fact, this was the first time I had seen bipolar electrolytic capacitors used in an audio path, and they are simply much more expensive.
The second issue that required repair was the non-working backlight of the built-in LCD display. This is also a typical fault. The high-voltage EL panel (foil) had simply reached the end of its life, so I selected a new panel of the correct size from Chinese suppliers. As a result, the instrument was restored to full working condition.
