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Hi,

I have a Yamaha P-155 piano for about 8 years now.

I played very actively for the first three years. Unfortunately, later I practically stopped playing. In the meantime, there were problems with sticky / slow keys. The key always returns to its place but does so slowly. in addition, if I press the keys at an angle, pressing is even more difficult.


I opened my piano. it turned out that no key is broken,
Finally, I decided to perform a complete cleaning and lubricant / grease change





step 1 - disassembly and cleaning of all keys

The keys are very easy to disassemble. In order to remove the black key, you must first remove the two adjacent white keys. There are a lot of videos on youtube on how to do this. But I decided to remove them all and clean them:



I washed all the keys first, It's not that easy because the grease is very thick. and is in a hard-to-reach place on each key.
first I washed all the keys in warm water with a little soap. and then with water under pressure, I washed away the remains of the old grease. now they are all clean;)



It turned out that there was also a lot of dirt on the hammers, and even more was under them:
then I decided to clean and disassemble the entire mechanism.







step 2 - remove all 88 springs to release the hammers.

The springs must be slightly bent, but be careful not to deform it



In the meantime, I ordered two dedicated lubricants.
luckily, they were available at one of the online stores for $ 40 each tube

V6274301 G-1006Y
AAX90710 G-1066Y








step 3 - take out and clean the hammers.

The keyboard mechanism must be unscrewed from the bottom housing first (all this is described in detail in the manual)
then you have to turn the entire keyboard upside down. Unfortunately, to take out the hammers. you have to remove the bottom stopper / smoother first. It is glued to the frame with double-sided tape (easy to remove) After all these years, the adhesive cannot be reused. so I definitely recommend that you simply replace it, which will have a positive effect on the lower volume of the mechanism.




it cost me around $ 24. (Still waiting for shipping) This Part is shipped with adhesive tape so replacement will be simple.
V764010R

BEFORE



AFTER




Finally I was able to take out the hammers
Here one important point The hammers are divided into four sections with different weight and in each section there are two types of hammers (white and black keys) so we have a total of 8 types of hammers. Fortunately they are marked with colors. below is a panoramic photo with all the hammers:



from the left:
1 section - green, red
2 section - black, purple
3 section - red, yellow
4 section - blue, no color


all the hammers have been removed!



I had to clean them all from dirt and grease, just like the keys. but I cleaned the hammers much faster








step 4 - cleaning the frame

now it's time to clean your frame. some dirt can be simply vacuumed up. but the grease has to be wiped off. There are several elements on the frame where each key touches it: gray rubbers, and directly the frame



still trying to clean the frame of grease. and waiting for a new stopper.


and my piano looks like this now :




Let me know if I should update the topic when the stopper comes to me ?

Great photos and narrative. The Japanese really mangled the "direct" English pronunciation of the word hook (they say "fu ku").

Keep us updated on rebuilding process.

Nice photos. That action is similar to ghs or gh3? Could make a photo to the sensors? Have you planned to clean them?
What about the pivot of the hammers? Is located at the bottom of the u bar of each hammer?

Yamaha GH in the P-155 is similar to GH3. Pivot of the hammer is within the white plastic part. The metal bar end is the one that swings up and down.



(From https://europe.yamaha.com/en/products/musical_instruments/pianos/clavinova/cvp-601/features.html)

Hi

This is the GH keyboard - an improved version of the GHS but not the GH3. So each sensor rubber has two contacts with the plate

To get to the sensors, unscrew the 3 brown boards.



I unscrewed one such plate and cleaned it. unfortunately I didn't take a photo but there was no dirt there and I never had a problem with too low or high sound. So I decided not to clean the rest


As for your question.

The hammers look very similar to the GH3.

Here you can see the GH3 scheme of operation, it differs basically only in that there are 3 contacts with the board




and this is the view of my sensors from the top, there are two contacts

Great job so far, thanks for sharing! Yes let's see the reassembly and lubing and sound test.

Very nice job, thanks for posting the pictures and detailed breakdown. This is an older and pretty well-known action, but I honestly think we cannot have enough resources online

Yes, nicely done. I've done some disassembly and cleaning and parts replacement. But nothing so extensive as you. I guess you had a great deal more dirt accumulation than I did?

Yes, I have a dog. and the piano stands in the open space for 8 years, never covered

quick update. I ordered two upper and lower stoppers. I received the wrong top stopper.

I ordered a VU34210R and I received V8468201

I thought it was a mistake but it turned out that in Europe yamaha only installs this stopper in Europe at the moment (I called an authorized service center)

in my opinion, the original one looks more solid.

I'm just talking about what it looks like. It is thicker and wider. the white soft part on top is also higher

Do you have any experience with this new stopper and is it replaced everywhere with the new part number?

That's interesting. I bought the V8468201 hammer stop for my old CLP240.
After eight years the old one was shot.
I was not aware that there exists a newer (better?) VU34210.

I wonder how it happens that yours wore out so quickly?

You misunderstood me

The originally VU34210R black-red-black-white was mounted in my piano. you can see it in the photo above because I haven't taken it off yet


and from the store I received one like you V8468201. - black-red-green-white but they differ significantly

I received information that production VU34210R has been discontinued - and replaced with V8468201

But as I wrote, my original part looks more solid. I only replace it just in case, mine is not very worn out yet

My piano is a 2005 model, whilst your P155 is a 2009 model. So I figured that your original VU34210R part was newer than my V8468201. Perhaps that's not the case?
Anyway, the "old" V8468201 works just fine, even if it doesn't look as robust as the VU part.

Also, at first I misread your model number. I was thinking P515 ... which was released two years ago. So how could your stop felt be worn out so quickly!?
But it's actually a P155, and it's eight years old, as you said. That's just about how long my felt lasted before failing.

I wonder why they stopped producing this part especially since it's a newer version. and it looks better to me. Now I wonder whether to replace it or leave the old one

I also saw somewhere on the internet a screenshot from the Yamaha system for ordering parts and it actually looks like this part has been discontinued and replaced: