I hope you guys can help point me in the right direction - got a PSR-280 which has an issue where some note keys are not working. Simple, I thought, get in there and thoroughly clean everything. When I was in there, the circuit board and the rubber caps all looked clean, but I did the cleanup anyway, but have been unable to get any of the missing keys working, they seem to be at random places, but mostly on the right-hand end of the keyboard. Tried alcohol, and even specialised electrical cleaner, but no difference.
I think the rubber pads are okay. If I use them manually on ‘good’ key pads on the circuit board they work. There doesn’t appear to be any obvious physical issue with the board, no corrosion, cracks etc.
Is it likely still to be the boards, or is there a known fault with this family of keyboards that cause dropout of keys? BTW, all notes work through MIDI control.
I would appreciate your guidance, and if parts are available, what would I need to bring this keyboard back to life?