Chosen Solution
Hi. The Db and G keys in the upper octaves (6 and 7) of my P115 are suddenly not sounding. Any ideas how to fix them?
Hi @susel61 , Looking at the wiring diagram in the service manual for the keyboard, (Be patient, it takes a little while to go from “processing” to “Download” once you have passed the reCAPTCHA test and click on Go to Download) I suspect that there is either a loose cable connector between the circuit board that connects those notes to the next circuit board in the keyboard or a dry joint wire on the cable connector itself at either end of the cable. Here’s a composite image taken from the manual where I’ve shown that the board where the keys are connected to, are connected to the next board and then so on to the processor. I’ve highlighted that all the affected keys use the same two wires to signal the processor and also where the cable connects between the two boards. Given that there is no other problem in those octaves then the connector must be plugged in OK BUT one of the wires (N11) is at the very end of the connector so the connector may not be pushed in far enough just at that end. If it is plugged in far enough then either n11 or n21 is faulty where it leaves the GHL88H board or where it enters the GHL88M board as after that everything is working.
(click on image to enlarge for better viewing) I’m not a musician but it appears as far as the circuit numbering for the keyboard keys are concerned, the octave numbering starts at 0 that is why I’ve highlight C#5 (D flat), G5, C#6 (D flat) and G6 because they are actually C#6, G6 , C#7 and G7 as far as the keys are concerned Sorry to be so technical but it’s looking like a wiring problem. The service manual details how to access the boards so that the connectors and the wiring can be inspected and tested. If this seems too daunting to tackle yourself, contact a reputable electronics repair service (piano repairs?) and ask for a quote. You could mention that the service manual is available online as that may help them if they are not that familiar with the keyboard
Hi @emdepqua, For that many notes to be affected it is either a cable connection problem between the DM board and the GHL88M board that connects to the centre keys on the keyboard or a power problem. I realize that you said that you checked for loose connections but did you check the connectors CN2 on the GHL88M board and the CN301 on the DM board as this is the cable that handles all the notes? Here’s an image taken from the service manual, that shows where the notes are connected to the processor. I’ve highlighted the connector and also the power supply voltage. Although the power would be OK I think as you said some notes still work and it is the same power for all the notes.
(click on image to enlarge for better viewing) Presumably there was no power at all connected to the keyboard when you did the repair? If still no good then any reputable, professional electronics repair service should be able to fix it if you either give them the circuit or the link to the service manual
Slaps did help me too. But I ask myself for how long. How can issue start -for all of us -in 2020?
Gave some hard slaps to the back of the keyboard, worked for me!!
