Hello,
I have a P45 Yamaha keyboard and the bottom half of the keys are not working. I had a broken key and replaced the octave, however, now the bottom half the keys are not working. Any advice?
Precisely which keys are not playing - keys are counted from left to right according to this
This is only the first couple of octaves but keeps on going to the far right - last key on the right being “C7”
Is this one of those keyboards that has two circuit boards for the contact pads? If so, did you remember to (a) connect both of the ribbon cables from these boards to the main board, and (b) to connect the little ribbon cable that connects these two boards together?
Nop - it has THREE circuit boards … if I know where the “no play” starts I can tell which scan lines are out and therefore if it is within a board or a cable/wire.
Hmmmmm … all the keys are selected then scanned in groups of 6. If you look at your issue you have two groups of 6 on the middle board (where your blue tape sits) and another 5 groups on the left board (the last group on the left is only 4 keys). So, there are 15 select lines, b01 … b15 (15 groups of 6) and 12 scan lines, n11 … n16 (first contact) and n21 … n26 (second contact) to scan each group of 6 when selected.
Your problem does not make sense in that scenario because the only way for everything to not work from C3 down to A-1 would mean 7 select lines affected, b01 … b07, would have to be cut somehow - but two of them are on the middle board and the scan lines are going all the way left to right.
Therefore - another question:
Did you remove that white cable going from the middle board to the DM board (yellow circle in picture)? If so, did you lift the clip to remove and also lift the clip to insert and then push the clip back in? If you didn’t lift the clip I would suggest you damaged that cable - it is somewhat fragile when not being careful.
Alternatively, when you did remove that cable and then pushed it back into the connector, was the blue “rigid pad” still glued on opposite side of the contacts or is it now missing therefore not making good contact?
I have not removed any of those cables. However, one of those keys in that octave was broken initially (which I replaced.) Perhaps the cable was damaged then? I will take a look.