Orijinal gönderinin sahibi: jayeff ,
Hi, The answer in this link may be of some help. [post|574172] It is for a P45B so hopefully it is close enough to your model to be relevant. The notes are “generated” by a +3.3V supply being fed through to the selected keys and back to the microprocessor on the appropriate input for the note. The circuit diagrams in the service manual should be of great help in finding the problem.