D50 NoteOff only

[mheidt]

Hello,
I have the issue that no NoteON is sent and only after releasing the key a sound is played. The keyboard works, if I Midi-In the the MIDI signal externally.
Test-Mode shows, that no signal is sent on pressing the key. No aftertouch either.
In this german forum a different person has the same issue and posted a video, which describes it best

https://www.sequencer.de/synthesizer/th ... te.156441/

I had to do several repairs in the past. Battery, soldering new knobs, cleaning/applying graphite to the key contact rubbers.
But this is a complete different category. It seems as if some board might be destroyed.
In rare cases the keyboard works but I couldn't find a relation to anything like temparture / time etc. As it is working sometime, it doesn't make it look like a board problem though.

Does anybody had this issue and could solve it?

Kind regards,
Markus