Piano World Home Page Forums Our Most Popular Forums Digital Pianos - Electronic Pianos - Synths & Keyboards Kawai ES100 developed "slow" keys

My mighty Kawai ES100 with its AHA-IV-F action is well into year 5 now (way out of warranty) and started developing "slow" keys. It has two keys (A2 and G#3) which offer slightly more resistance half way down (leading to a quieter tone). Repetition is also much slower on them than it used to be.

Questions:

Does it get worse than that? The keys function still fine otherwise and still trigger reliably.

Is there a way to fix those keys?

Am I looking for an excuse to employ G.A.S.?

My es100 keys are looking a bit crooked these days. So I also will need to figure how to realign and lubricate. Any tips welcomed.

Maybe these will get us started

1. Extensive AHA-iv photos from cl35:

https://forum.pianoworld.com/ubbthre...ey-repair-advanced-hammer-action-iv.html

2. Service manual for different AHA-IV keyboard that might have an image or two that is useful

https://www.manualslib.com/manual/1249302/Kawai-Es4-Es1p.html

3. Entirely different Grand Feel action but some interesting education

http://forum.pianoworld.com/ubbthreads.php/topics/2272105/1.html
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Great info, @newer player That looks like a bigger repair job.

Even though it’s not under warranty, why not call Kawai in Europe? Their tech support may be able to offer suggestions.

I'm unsure if a commercial repair is cost-effective for an instrument, which starts at just above 550 € new.

Can this be fixed? Yes and no.Yes, repair is possible. But if you're feeling the G.A.S ... then repair is completely impossible.

If you take Beano the G.A.S. will go away. If so, then you might consider lubricating the keys. Mine needs lube every couple of years.

I intend to keep the instrument, even if I decide to get another one, so it most likely gets fixed one way or another. Currently the issue just a minor annoyance. I just hope I don't break stuff by continuing playing it.

However one year into owning the ES100 when the first G.A.S. showed up I decided to wait with an "upgrade" until wear and tear make the decision for me. I just didn't expect it to come around so soon already.

Did I misread your initial post mentioning that you have used the ES100 for over 5 years?

The instrument is in its 5th year now, so it has been in use for over 4 (completed) years. I know, my wording is confusing due to my questionable command of English language...

More than 5 years would be pretty impossible, as the the ES100 model came to market in early 2014, if I remember correctly.

It was in late 2015 already, when I started looking for an "upgrade". Then I made a deliberate choice to not research more DP models or VST plugins and spend my time on piano practice instead. (As long as the ES100 lasts me.)

Thank you for the clarification.

Kind regards,
James
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So, after removing 28 screws, the culprit has quickly been found:



The rubber attached to the hammers became sticky from the lubricant. Now I have to improvise something

Want to have look inside an AHA-IV-F action?



Look at this gorgeous key length. That's 211 mm from the front (without the lip) to the fulcrum for a white key and 160 mm for a black key. Pretty impressive for a sub $1000 board.

Here you can see, that the plastic pads glued to the rubber moved out of the way, revealing the glue under it, therefore sticking the keys to the rubber.



Realigning the pads, the original glue still works:



Problem solved.

Nice work!!

PS thanks for sharing too - hopefully anyone else who may have the issue can replicate your good work.

But, how long for. The reason they moved remains, my dear Watson.

The reason might be missing lubricant on the key pins. I moved some of the excess lube to the keys, so at least those keys and hammers should last a while now.

Nice. Any tips on removing, lubricating, and aligning the keys.

Key removal is done by inserting a tool between the latches at the fulcrum and bend them apart until the key comes off. Then the key can be pulled towards the front. Keys can't be aligned, they snap into place. Lubrication is applied at the front rail, at the fulcrums of hammer and key, and at the pin pushing the hammer.

My ES100 had the same problem as the CL35 described in this thread: https://forum.pianoworld.com/ubbthre...ey-repair-advanced-hammer-action-iv.html which occurred after about five years as well.

So it seems five years is the service life of the AHA-IV-F action.

Thanks JoeT!

I suppose the crooked spacing is a function of wear of plastics and felts etc.

Nicely documented, Joe.

Two other keys (E and F) have got issues. They are not "slow" yet, but they developed some kind of "escapement" feel, so their bushings seem to be misaligned as well.

Seems the ES100 is now going through monthly repairs now until I've gone through all 88 keys or I stop using it entirely.