Kawai CS10: Sticking Keys

By Ted Felix March 5, 2021


I needed to disassemble my CS10 to fix some sticking keys. Here's how I did it...

Disassembly Notes

Note that these instructions probably also apply to the CS9, CS11, and maybe some other Kawai digital pianos that have real piano cabinets.

The Kawai CS10 can be disassembled by following these steps...

  2. Remove the back
  3. Remove the (front) upper panel assembly (carefully)
  4. Remove the fallboard (keyboard cover)
  5. Remove the key stop rail (piece over the keyboard)


Remove the back. There are 9 gold sheet metal screws that come out easily. The back also comes off easily. We could jump to removing the key stop rail if we had a way to remove its center screw. But it is rather hard to get to, so we'll have to keep going.

Remove the upper panel assembly. Disconnect tweeters, remove the 6 screws, carefully push forward from bottom. This is a bit tricky and seems like it might scratch the arms. Be careful here. Note that the two shorter screws are for the center. (Reinstalling this is particularly noisy and nerve-wracking. I think the two plastic trim pieces on either side are the problem. Installing the two (shorter) center screws first seems to be helpful as they lift the panel into a better position.)

Remove the fallboard. Close the fallboard over the keys. Remove the 4 screws attaching the metal brackets to the arms, two on each side. While supporting the fallboard from the center, Carefully lift the fallboard out. It is heavy, be sure to support it in the middle or on both sides so that it doesn't tilt and scratch anything.

Remove the key stop rail. Another four wood screws, two on each side, and the sheet metal screw in the middle.

At this point you should have full access to the keyboard and you should be able to pull keys and replace the Teflon pads (PTFE sliptape) for any sticking keys. Some folks use plain felt tape instead. Be sure to clean any glue off the metal button on the hammer with IPA. See the videos below.

When pulling the keys, hold the hammer up, lift the key up from the front until it clears the balance rail pin and then pull out. Be careful not to upset the paper rings that are used to adjust the key height. These are on the balance rail pin. Sometimes they stick to the keys. Be sure to find them and replace them if they come off.

The hammer is hooked upward in the back. Lower it and it should unhook downward and pull out. When reinserting the hammer, hook it in the back, lower the front and lift the back up into position. Then insert the key underneath. It's a little tricky and takes some practice. If it looks wrong, it probably isn't hooked on in the back. Try again.

Reassembly is reverse of disassembly. See the reassembly notes above.

3/6/2021 I was able to fix three of the keys by either removing and resticking the teflon layer which had shifted, or by reattaching the teflon layer that had separated from the felt with double-stick tape. These are temporary fixes and I will be ordering some sliptape from Kawai for the final correct fix.


Took some pictures of the motherboard. Appears to be a 200MHz Renesas (Hitachi) SH7203 microcontroller running the show (marked 72030W200FP). Two 32MB SDRAM chips: ESMT M12L2561616A-6T for a total of 64MB SDRAM. And four big KAWAI chips: K023-FP, KP682-FFFW, KP681-F9FP, and KP707B-FBFP. The KP chips feel like they are the ROMs since they have stickers on them. Not sure if "FP" indicates field programmable (ROMless?) or floating point. I'm not really a hardware guy.


How To Fix Sticky Keys on Kawai MP11, MP11SE, CS10, CS7, CP1, CP2, CA97, CA67, CS8, CS11, CA78, CA98 - YouTube video explaining how to replace the Teflon pads.

Fixing slow [Kawai Grand Feel] keys adding PTFE layer - Same idea, but includes instructions on confirming correct velocity when done.

Fix sticky key Kawai CA97 (Repairing guide GF1 GF2) - Work starts at 3:20. A Kawai tech chimes in (in the comments) and provides the proper procedure for complete sliptape replacement.


Copyright © 2021, Ted Felix

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