I’ve been trying to repair a Yamaha P515 that has a cluster of 6 dead keys, all grouped together in a neat cluster. At first, I suspected a failure on the key contact board, since the P515 splits the keybed into three separate boards: High, Mid, and Low, and those divided into sections of key contacts. The affected keys were all located in that section on the high board. (It was all the keys in said section), so I ordered a replacement and swapped it out. Unfortunately, the issue still persists.
I’ve ruled out the rubber contacts. I tested by swapping around the old and replacing with new ones.
I’ve also ruled out connector issue between High and Mid Boards
Sometimes, one of the boards on keyboards has the scanning chip. It could be this that’s at fault since it scans keys in groups and one faulty line can drop out a set of keys.
Looking at the photos of the Syntaur replacement boards, I can see that the middle board has a chip on it whilst the top and lower do not. Perhaps Syntaur can swap with extra cash for the middle board?
Did you get hold of the service manual? This should help you isolate the problem.
Exactly which set of 6 keys is not working - considering the lowest C = C0 … the scanning sets are “C#x - F#x” and “Gx - Cx” hence the lowest set of 6 is “C#0 - F#0”. As an aside - the P-515 has the key scanner on the middle board … hence I suggest the problem is the middle board.
G5–C6. A local technician also suspects the scanner might be the issue. Unfortunately, Yamaha doesn’t seem to be prioritizing sending spare parts to distribution centers right now. I was told I might have to wait until next year at the latest.
I could order the part from Syntaur like I did with the H board, but I’d really prefer not to pay triple the cost in shipping, taxes, and import fees.
YAMAHA is in the middle of a rather large re-organization … I am not exactly sure myself what the outcome will be but parts delivery has slowed down considerably, even for certified repair shops like myself.
You could try following the one signal controlling that block with a DVM.
There are two connectors between the boards - looking at CN202 Pin3 on the HIGH board going to CN7 Pin3 on the MID board then to pin34 on IC1 on the MID board - that path should have continuity.