Music suddenly stopped, only some noise (K4020).
I suspect the pre-amplified K4100 because there is also nothing coming out of the headphones (except same noise).
All the rest of K4100 works perfectly (all keyboard functions); trafo 2 (12/0/12) gets very hot (compared to trafo 1).
Any idea what may cause the problem or where to start looking) ?
This can have so many causes.
Check all power supply voltages on K4100, starting at the transformers, regulators and different locations on the board.
Make sure a mechanical cause is not at the origin of troubles.