Hi All glad to join the community. Hopefully that someone can help.
The power indicater turns on ( red light in front) but the indicators on the main panel (keyboard and the lights of the function keys) do not turn on at all and no sound when pressing the keys.
Hi,
hope you appreciate this unit is over 30 years old - hence problem could be any place.
For a possible fix (and I mean possible) you need some good electronic knowledge.
The red light being on but nothing else works is not near an indication to a possible fault location - well at least we know we most probably have +5VDC.
To start with I would suggest to check whether all the required voltages are present (see circuit below)
After that it is getting more complicated. Could be anything from bad capacitors to bad IC’s. Maybe do a physical inspection whether you could see some corroded IC pins …