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Instrument is a Pramberger PS-175, purchased new and delivered 7/2016. Humidity control device installed. 5'9" small grand, Signature Series. IKNEG 0256.

Within a few weeks I started to have an intermittent problem in which I would strike a key but no sound is produced. I can hear and feel parts moving, but it feels as if something blocks the strike. The very next time it plays fine, as though nothing had happened. Affected several keys in the B4-D5 range.

Dealer sent their technician and he thought it was tight pins in the whippen. He spent a couple of hours disassembling whippens, pulling pins, reaming holes, replacing pins. He worked on about an octaves worth. All was well for a week, then C5 began again to not play when struck. At first infrequently, but at least once daily; now about one of every five to ten strikes of C5 fails to produce sound.

I have a call into dealer but am concerned to have this problem on a new piano, and especially to have it recur in one of the same keys that has been repaired once already. Credit due that the other keys have not recurred, even the worst offenders.

1. Is this unusual in a new instrument and should I be concerned?
2. Does it sound as though their technician is on the right diagnostic and repair track?
3. He said that if it recurred, he would pull the action and take it to the shop for complete going over, but a respected RPT and Piano Technicians Guild member said this problem should be repairable in the home, shop not needed unless technician needed a consultation. (Tech has been doing this 16-17 years, but as far as I know is not registered or a guild member.)

Any suggestions?
Any Pramberger people out there who wish to weigh in?

Sounds like it might be stiff joints on the jacks, or weak springs, or jacks too far forward. The last is easiest to test: Block the hammers from going all the way up, and see if the key goes all the way down. It should not be difficult for someone who knows what is what to fix.

Perhaps the capstand need adjusted due to changes in humidity (even with the humidity control device)?

Does/did this problem manifest itself after the piano has been played for a little bit, and then hours later the keys worked again?

Normally the piano worked fine when leaving the factory, so it is surely a moisture problem.

My advise is to not mess with springs, capstans or other regulation points.

IMO the tech is right. It's a tight jack pin. Probably he didn't ream/burnish the bushing enough.

This job must be done at home. No need to take the action to the shop.

The first year of a new piano often shows this kind of moisture problems: sticky keys, dampers and/or hammers not falling down, jacks that do not reset correctly, etc.

This is normal for a new piano and it is due to felt swelling by absorbing air humidity.

I think some of this has been covered, but here are some thoughts:

1. I don't know how common of a problem this is on new pianos, but no, I don't think it's a cause for concern. As far as I can tell from what you described, something about the action (several causes have been mentioned) is causing the jack to not reset under the knuckle. Whatever is wrong with it can be corrected -- probably easily -- and it's not an indication that anything else is wrong with your instrument.

2. Probably so if it fixed all but one of the notes! Keep in mind it's almost impossible to correctly evaluate another tech's work unless we can physically inspect it. No matter how hard you try to provide details, too much information is lost in transmission.

3. Oh, it almost certainly is reparable in the home. But that doesn't mean there's anything wrong with him taking it back to the shop, assuming the dealer is paying for all this anyway. That way he can do the procedure, let it sit for a while, test it out to make sure the problem didn't come back, etc.. Even if he wants to consult with another technician, that's fine in my book. I know techs (RPT's, even) who do quality work but aren't all that confident at puzzling out action problems that go beyond simply regulating to the manufacturer's specifications. Pianos are complicated, nobody knows everything about everything.

Excellent advice from Rafael and Nathan. However if the answer to my question above is yes, I think the piano has "mystery sluggishness" The only known cure that has very little chance for subsequent attention is to repin the action centers. I prefer to do this in the shop.

I would give the technician the benefit of the doubt and let him try to fix that residual issue one more time. If more happen then deal with the problem as Ed suggests and it has to be done in the workshop. But I think that if that were to happen then the dealer should replace the piano.

Thank you, all.

Firstly, I have no concern about the technician, having practiced medicine myself for many years and knowing that one does not always get it right, either diagnostically or therapeutically, the first time no matter how good one is. A piano is not quite as critical as medicine in the overall scheme of life.

Secondly, it was asked if this happens at the start of the day or after the piano has been played for an hour or so. Answer: I start my day doing Hanon Book 1 exercises, currently at one beat per note at 120 bpm. Problem occurs intermittently during these exercises. It may worsen slightly as the day goes on, but that is not obvious. So I would say the answer to Ed's question is 'No'.

Thirdly, humidity was mentioned. The humidity control device has about an 8 percent range, from 42-50%. I am told by my normal RPT (who has not worked on this problem since it is still a warranty issue) that is about the best to expect in Houston TX, but that should not be the cause of the problem. What I have trouble understanding about a humidity connection is why is this an on/off phenomenon? Everything plays perfectly fine for a good while, then suddenly C5 doesn't sound, then plays perfectly normally on the next strike. There is nothing sluggish, as I would use the term; it is more on/off, it either strikes or it doesn't. I might note that this piano was bought in Houston, so it was in the same general humidity environment prior to purchase. The two potential differences are (1) I am a bit further inland and so our humidity is marginally lower, but not substantially, than the dealer, and (2) my house is probably a few degrees warmer than the showroom, hence maybe a bit higher humidity, but, again, not substantially. I have a hygrometer sending unit inside the piano and check the humidity regularly, so I have a pretty good idea what it is running, and note that it runs at least 8-10% lower than the humidity in the rest of the house. The 8 percent range I quote is from measured humidity in the piano at the narrow end of the instrument.

Fourthly, I don't consider it a negative for someone to want to get a second opinion, especially the someone doing the repair. I certainly did it in medical practice. And it is warranty repair being performed by the dealer so I accede to the way they want to do it. My only concern is someone doing considerable reaming and pinning on a new piano IF that didn't seem like the right solution. I do find comfort that it seems to have fixed the other keys, especially the worst one, and that suggests he is on the right track.

I was spoiled by the Yamaha M204 I had, which did not have ansingle issue in 38 years of ownership, but I know there is a world of difference between a vertical and this Pramberger, my first grand, or should I say 'horizontal'!

All of your advice has been most beneficial and comforting. I'll try to close the loop when resolution has been achieved.

If a key plays but intermittently "skips" as the original poster seems to be describing, it is most likely but not necessarily because the jack is not resetting properly. The question, if the jack is the culprit, "Why?". Tight wippen flanges would rarely be the cause but I did not see the piano. Even if they were a little stiff, I don't see that as causing the symptom.

I respect the original poster's analogy to diagnosis in the medical profession but the piano action, as complex as it may be, is not anywhere near as complex as a human body as far as determining what is causing the symptoms.

The length of time a person has been at the job is also not necessarily reflective of what a technician may know and how well they can diagnose a problem. Dealers do not like to hear of such problems and figure much like the owner of a new piano would, "It's new, so any bugs should work themselves out by themselves if you just give them a chance". Dealers hire piano tuners more than they do piano technicians.

So, the trusted dealer technician is asked to diagnose a problem but may not really have a clear idea of how to do it. In a vertical piano, for example, a tight wippen flange may well cause the symptom and so may a capstan adjustment that is too high. But a grand piano action works fundamentally differently from that a of a vertical piano due to the presence of the repetition lever.

In short, neither a tight wippen flange nor a too high or low capstan would likely be the problem unless perhaps, the tight wippen flange condition were extremely severe which is not very likely. A too high or low capstan would not cause this symptom in either case, no matter how severe but would cause some other kind of symptom.

Actually, the probable causes have already been mentioned. Houston has a very severe moisture problem but also a heat problem, so I assume that the indoor environment is not quite so severe. That being said, the piano may have been exposed to some high moisture in transit and storage which could have resulted in some swelling that has not yet been relieved as well as some corrosion.

The humidity control system largely controls soundboard moisture levels in a grand piano and will have little no no effect on the action whereas in a vertical piano, it can also keep the action from drying out or taking on too much moisture. In a grand piano, the humidity control system may only aid the action is the piano is closed and completely covered when not in use, the way they sometimes are in public venues.

If the jack hangs up sometimes because of either, a drop or two of a special lubricant that most technicians have and use would be all it really needs. After the piano is continually played (as it seems it will), the problem would not be likely to recur.

Sometimes, two or more problems contribute to the symptom. If one problem is detected and addressed but not the other(s), the condition may seem improved but not entirely. That is true for many conditions which arise in pianos.

Therefore, if the jack flange is marginally tight but also marginally protruding above the surface of the repetition lever and is marginally positioned too far proximally and the repetition spring is marginally too weak, all may need to be checked and addressed for any one of those conditions can cause the symptom. Two or more of those conditions will exasperate the problem.

There is also another problem that can seemingly cause a key not to play which can occur with the back check angle. Sometimes, the angle of the backcheck is just a tiny amount incorrect so that it "grabs" the tail of the hammer during certain but not all keystrokes. That condition causes an odd feel upon the key, a certain resistance and when it occurs, the key will not play, even if everything else is correct.

In order for the technician to properly diagnose the problem, they need to be very thoroughly experienced in how a grand piano action works. The solution for the problem will most likely be a rather simple one, rather than anything complex but yes, anything is possible.

I just reread the original post. It seems that one technician is speculating that the dealer's technician is taking the action because he wants to consult with a third technician, who may or may not exist.

The dealer's technician isn't saying he wants to consult. The other tech is only guessing about his motives and has alarmed the customer.

The technician may want to take the action because he wants to do major work like re-pinning with all new pins, or checking and resizing all the center pin bushings, or something else that is not conveniently done in the home. But, I am only guessing.

The piano owner should contact the dealer's tech directly and ask for more information from him.

If worse comes to worse, you can always just take the modular approach. Instead of endlessly troubleshooting one part with a mystery problem, the whippen can always be replaced with a new whippen, if the problem still isn't solved.

But, it doesn't sound like we're at that point yet. We don't have a diagnosis from the tech who is working on the piano.

The best choice at this point is to ask the dealer's tech for more information.

I am waiting for the dealer tech to call. Not the speediest of responders, this dealership.

This piano was on the dealer showroom floor when purchased. I took a photo of the serial number plate, so I am pretty certain the same piano was delivered. That being the case, there were fewer than 10 days from purchase to delivery. I doubt it went into storage, then back out for delivery, but if it did, it was for not more than a few days.

Bill's description of "an odd feel upon the key" is what I feel. The key travels its full extent but I sense that something prevents the strike, a resistance, as Bill puts it. To Bill I would ask whether work done on wippens, reaming and repinning, could have solved this possible back check angle problem as a side benefit? Could attribution of correction of this same problem in other keys by the wippen work actually have been an inadvertant adjustment of the back check angle that corrected it? My ignorance of all these parts and what is where and connected to whom is readily admitted, but I can at least ask the technician about these things. As a physician, I appreciated patient input; it often led to the forrect diagnosis and saved considerable time and false leads.

To daniokeeper: lots of unnecessary speculation on your part, most of it inaccurate, but thanks for your thoughts.

By the way, the overwhelming majority of medical problems are not that complex to either diagnose or treat. Just as I would not want to perform a complicared procedure for a medical issue with a simple solution and treatment, I am not particularly eager to have a brand new piano considerably rebuilt if there is a simple solution.

I have nothing to go by except for what you wrote.

He doesn't need to take the action home to consult with another tech. He could even consult with the manufacturer's technical department or make a post here at PianoWorld.

But, I do wish you the best of luck with your piano.

When someone says "if it re-occurs" that means he is not sure he has fixed it, or fixed all of the sticking issues.

Is it possible the notes he re-pinned are working fine, and the issues are on different notes?

In my experience, if pins are tight on some notes, other notes can seize up later, and more can seize up after that. Often the client or the dealer won't pay for all the pins in the action to be checked for proper friction, and that results in multiple trips back to the home. I've a Sejung Hamilton in a church I tune every 12 to 18 months, and each time I find new notes with tight Jacks and hammer flanges.

It's much easier to to a good job on an action repair on the bench where there is light, an adjustable stool, a firm work bench. There is a limit to what I'll do in someone's home.

Docc,

I mentioned the rare but definitely possible problem of a back check "grabbibg" the tail of a hammer because I have encountered it any number of times before but certainly not very frequently as a culprit for a "sticking key" (which many clients will say about any key which does not respond normally).

It does "feel" really odd when it occurs. I had a case of it just last week and the culprit was not the first guess as to the problem. In this case, the client said I had tried various other solutions and they seemed to make the condition better. But, after a few years (yes!) of my last tuning having deteriorated enough that the client wanted to have me back, but there was still a problem with a particular key.

It was a fine and quite expensive Shimmel grand. When I tried the problematic key, I could easily sense what the problem was but still, even I did not know what was causing it. I tried all other functions, key freedom, hammer and wippen flange freedom and all were normal.

Still, I could feel what the client did with the action out of the piano and I soon identified the problem as the backcheck. All it took was a gentle movement with my hand and fingers to alleviate the problem. No tools actually involved, although they could have been.

I recall a similar instance with a thoroughly rebuilt piano on a stage and used for public performance but with a key that "would not play". It was an emergency service call! Once again, at first, the feel was odd but I acknowledged that it was there. I removed the case parts and tried the problem key with the action removed from the piano and immediately recognized the problem for what it was. It took only a gentle movement from my fingers alone (no tools) to alleviate the problem. I was done with the service call within a minute or so.

With my client last week, I must have also tried various remedies upon my last visit but this time, with the action once again removed, I spotted the problem immediately. It also took just a gentle push from my fingers to resolve.

So, be sure to mention "back check function" as a possibility for the diagnosis of the problem.

Bob: the note that is malfunctioning presently is in the octave of notes that the tech said he had reamed and repinned. Therefore, this would be a recurrence in the same range, not a new occurrence in a different part of the piano. Also, I interpreted his comment about 'if it recurs' to mean that he worked on certain keys where I was having the problem; if it recurred in other keys then he would work on all 88.

Since I am not piano tech educated, I specifically avoided using the expression that a key was sticking, not wanting to give false impression or generating a red herring; the key works perfectly fine. The problem is that even though the key depresses fully without restriction, there is an odd feel that something elsewhere restricts the mechanism and the hammer does not strike the strings. Very similar to what Bill has described.

You have ALL been most helpful. I will share this information with the tech. Even though this is still a warranty issue, if I am not comfortable I will pay for a second opinion from the RPT I know best. If this is a simple fix, I don't want an unnecessarily complex solution. I believe in second opinions.

Docc,
If I am reading your earlier response correctly, you do feel that the problem does get worse as you play. If so, that is a symptom of "Mystery Sluggishness". It is not an uncommon problem in Korean made pianos.

You can check for a back check issue as follows:

1. Find a 12" long, skinny rod or something similar that will easily fit between the strings.

2. Gently press on top of the offending hammer with the rod inserted though the strings - not much pressure at all.

3. Press slowly on the key, let the hammer move upwards while keeping a bit of pressure on the hammer.

4. If you feel sticking or rubbing as the hammer moved towards the strings, you have a back check issue.

Ed: No, the problem is present when I start the day. It occurs intermittently throughout the day.

When I had this problem with D5, on the morning the tech was to come I repeatedly hit D5. When previously it was an intermittent problem, on that morning the problem became repeatable. Many times consecutively it failed to produce a sound, even though the key depressed and rose normally.

Just this morning C5 repeated that scenario. Until this morning it was an intermittent problem, occurring maybe once or twice in every ten key strokes of C5. This morning, during Hanon exercises, C5 repeatedly failed in the same pattern as did D5.

I don't know if this changes any of the suggestions that have been made.

Again, thanks to all for the excellent input. I will show this thread to the technician.

Dealer is sending his concert tech next week to take care of the problem. I will try to update after he has been here to let everyone know what he found and did, hoping that having the report of the one whose eyes were laid on the instrument will be helpful.

Have a great week, all.