20 Most Recent Yamaha Full-Size Keyboard - Page 5 Questions & Answers

This may sould dumb, but did you check the Headphone jack? If the 1/4" adapter for 1/8" may be left in the port, like on my keyboard. I took it out and sound came on. Lame, I know, but . . . .

The wire from pin 1 or 7 of CN1 on the GHL88L (left end) circuit board is open where it goes to the middle circuit board. This could be a bad cable, improperly seated cable connector, or a crack in the circuit board(s) connecting to these wires. These are the common matrix wires associated with only the C# and G keys for the left 1/3 of the keys. If more than 1/3 is dead, then the problem is likely on the middle board GHL88M that connects to the mating cable to the CN1 connector.

There are two wires dedicated to the keys for the two contacts that are used to measure velocity of the key strokes. There is a mechanical position between closing the contacts and the time is measured by the processor as velocity.

If you are the least bit worried about working on electronics you best have a service person do the repair. The keyboard has to be lifted out after removing the top and disconnecting other cables.

The part numbers are only available through the Yamaha Corporation. The Service manual, which is available for purchse (note that this is NOT the owner's manual) will have them.

I repaired mine on my own. I used a sticky foam tape of the correct width (approxiately 3/8 wide) and overlaid one layer directly over the original felt pad. I used a white foam tape like is used for carpet or other indoor needs. If I were doing it again I would probably use something just a little thicker and softer than what I used (appx. 1/16 thick).

Disassembling the Clavinova and removing the entire GH88 keyboard for this work is not hard if you are even moderately handy. I had the entire mechanics of the unit laid bare in 45 minutes with no manual (and not one curse word).

I am going to write up a tutorial on this soon as many people have asked about it.

By th way, I have heard that the factory pads are $100. My solution cost me about $3. Even if I have to do it again in a year, it's a win.

Call around to local music stores and ask about the closest authorized Yamaha repair center. If it is still under warranty, they should replace the keybed free of charge.
Here is a great website with the do's and don'ts about self keyboard repair. http://www.mikebarden.com/view.php/area/1/digital-piano-repairs-keyboard-repairs

Hi Simon. Has the cable to your Mike been trapped under the stand, trodden on etc. Could be a faulty plug or even Mike/switch. Did the Mike ever crackle under use?

Have you another Mike and lead to try?

Sorry for the obvious questions but I have seen this happen before and it was a faulty lead...

I have the same problem, mine is Yamaha YPG-625. This seems to be a common problem with Yamaha keyboards. I opened the 100 screws in the back, separated the main board from the display unit which is under it if you flip the keyboard upside down, to verify if there was any loose wires, nothing of the sort.
It is so frustrating, the keyboard is working fine but it is hard to navigate because the display is not functioning. Yamaha should do a recall as this is obviously something wrong with the keyboard happenning to a lot of people