What would cause a key to be dead sometimes?

Posted by: Ragdoll

What would cause a key to be dead sometimes? - 11/20/12 09:22 PM

I have purchased a different piano (Yamaha U1) and have just recently noticed that D6 and E6 are both having a problem of occasionally just being dead...no sound at all. This happens intermittently so I'm sure when the tech comes to tune it it will refuse to misbehave itself. Any thoughts on what could be causing this to happen?
Posted by: rysowers

Re: What would cause a key to be dead sometimes? - 11/20/12 09:27 PM

My biggest advice to clients is to write down exactly which notes are giving you trouble. Often when a technician enters the room the piano decides it better start behaving itself! Even if its not acting up at the appointment, if we know which notes were the culprits, we can usually fix the problem.
Posted by: Loren D

Re: What would cause a key to be dead sometimes? - 11/20/12 09:29 PM

It could be several different things. Broken or weak jack springs, sluggish action centers, no lost motion, something between the keys, etc. Only a tech would be able to tell for sure once he/she sees it. A good tech will correctly diagnose and fix it, though.
Posted by: Zeno Wood

Re: What would cause a key to be dead sometimes? - 11/20/12 09:32 PM

In addition to writing down which notes it is, see if you can figure out circumstances in which those notes don't work. For example, playing softly/slowly, or fast/loud, or if it happens after playing the note a number of times, or if it happens only the first time you play it, etc.
Posted by: Bob

Re: What would cause a key to be dead sometimes? - 11/20/12 10:12 PM

Broken butt spring cords?
Posted by: Emmery

Re: What would cause a key to be dead sometimes? - 11/20/12 10:21 PM

If its occasional then its likely the jack not resetting. This is not a big issue or cost to fix. Call your tech for a tuning and they will take care of it.
Posted by: SimplyBrendan

Re: What would cause a key to be dead sometimes? - 11/21/12 04:45 AM

Humidity causing all the above? Might want to check that for future similar problems. New piano, new environment perhaps?
Posted by: Mark Cerisano, RPT

Re: What would cause a key to be dead sometimes? - 11/21/12 07:44 AM

Here are two quick tests you can do yourself (for those who like to know more what's happening)
1. Press the key down and then lift it up slowly. Does it play now? If not, it is probably negative lost motion (or #2); the jack is not reseting. Also, one can usually get the note to sound again by playing the note a few more times rapidly and loudly. To fix, just lower the capstan a quarter turn or so.
2. Play the note twice reasonably fast, say 4bps. Does the second note sound? If not, it may be a sluggish jack not reseting fast enough. To confirm, wait a few seconds and try again. If the note does sound after the wait period, that is because the jack has now slowly reset itself. Repairing that is more difficult.
Posted by: Ragdoll

Re: What would cause a key to be dead sometimes? - 11/21/12 08:54 AM

Originally Posted By: SimplyBrendan
Humidity causing all the above? Might want to check that for future similar problems. New piano, new environment perhaps?


It was delivered 2.5 months ago. It has a climate control system installed but thanks for your response.
Posted by: Ragdoll

Re: What would cause a key to be dead sometimes? - 11/21/12 08:58 AM

Originally Posted By: Zeno Wood
In addition to writing down which notes it is, see if you can figure out circumstances in which those notes don't work. For example, playing softly/slowly, or fast/loud, or if it happens after playing the note a number of times, or if it happens only the first time you play it, etc.


That's what is so puzzling to me. It happens after I have been playing a song and used it prior to when it goes dead. I have an appointment with a good RPT in a few weeks so I will write every cicumstance when it occurs so I won't forget.

Thanks to evryone for the helpful suggestions as to what it might be.
Posted by: Jerry Groot RPT

Re: What would cause a key to be dead sometimes? - 11/21/12 08:59 AM

Let's see... Muting rail felt getting in the way? smile
Posted by: Ragdoll

Re: What would cause a key to be dead sometimes? - 11/21/12 09:00 AM

OOps...should have said "while" playing a song. Also it seldom occurs when playing softly
Posted by: Ragdoll

Re: What would cause a key to be dead sometimes? - 11/21/12 09:03 AM

Originally Posted By: Emmery
If its occasional then its likely the jack not resetting. This is not a big issue or cost to fix. Call your tech for a tuning and they will take care of it.


Well thanks for that. I'm not quite broke but certainly cracked a bit after this purchase. eek
Posted by: Jerry Groot RPT

Re: What would cause a key to be dead sometimes? - 11/21/12 09:14 AM

If you can get it to do it before he comes, do it. Then, LEAVE it that way. Tell him it is sticking now. He'll dismantle the piano to see the action and look around to see if anything is obvious. My guess would be the jack too. Not enough lost motion. Often times, it will happen more when the sustaining pedal is also used.
Posted by: Bob

Re: What would cause a key to be dead sometimes? - 11/21/12 09:16 AM

Originally Posted By: Ragdoll


Well thanks for that. I'm not quite broke but certainly cracked a bit after this purchase. eek


Ragdoll is now googling "jack", "mute rail" "broken butt spring cords" for how to repair.......

Just don't use wd 40 to lube anything! grin
Posted by: Ragdoll

Re: What would cause a key to be dead sometimes? - 11/21/12 09:24 AM

shocked But,but, but... Dismantle my piano? LEAVE IT WITH NO PLAYING 'TILL HE COMES!!! Kidding of course. FWIW, the key returns just makes no sound.
Posted by: Jerry Groot RPT

Re: What would cause a key to be dead sometimes? - 11/21/12 09:57 AM

Right. Probably a jack problem, lost motion, or sticking key bushings would be my first "guess." Nothing serious if that be the case.
Posted by: Ragdoll

Re: What would cause a key to be dead sometimes? - 12/28/12 12:26 PM

Hate to think of this as a dead or old thread but thought I would update the RPT visit yesterday. The tuning itself is delish and the piano really sings now...however Ray was unable to cure the dead key issue due to time constraints. And of course we could not get it to misbehave except one time.

He did lube the jacks and capstans (whatever they are)in octave C5 to C6 and probed a bit on some tiny springs with a little icepick thingy (a technical term) but it did not fix the problem with the random dead keys. I scheduled a new appointment per my guarantee to look further into it. So most of all everyone's suggestions were right in the "area" of problem.

We also played a few songs (duets) to assess my own fingering techique and to see if the lube helped at all but sad to say it didn't. He did compliment me on my playing after I said "sorry" for my own pathetic mistakes. blush Still it made me feel pretty good as he is a very good pianist besides a great tech. I'll update after the next visit.

FWIW, I had never seen the inside of an upright and was amazed at the complexity. So much action to produce even one tone wow
Posted by: rysowers

Re: What would cause a key to be dead sometimes? - 12/28/12 12:40 PM

That is really unusual that your dead note problems didn't get fixed at the appointment, especially since you knew exactly which notes were giving you trouble.

When I show up at an appointment where there is a sticky key complaint, that is the first thing I work on. Once that problem is solved I will address things like tuning and voicing with the time that I have left. Sticky keys are always a priority over tuning, in my opinion.
Posted by: Silverwood Pianos

Re: What would cause a key to be dead sometimes? - 12/28/12 01:06 PM

Originally Posted By: rysowers
Sticky keys are always a priority over tuning, in my opinion.


Agreed. I am left wondering how the fellow tuned those notes without repair.

Especially when one reads something such as this part;

Originally Posted By: Ragdoll

He did lube the jacks and capstans (whatever they are)in octave C5 to C6 and probed a bit on some tiny springs with a little icepick thingy (a technical term) but it did not fix the problem with the random dead keys.
We also played a few songs (duets) to assess my own fingering technique and to see if the lube helped at all but sad to say it didn't.(snip)


And all of this went down while the tech was there? About 15 minutes to remove/replace the action and repair the whippen pin… hook up the pedals….
Simple to call forward the next appointment and be a bit late.
Posted by: Ragdoll

Re: What would cause a key to be dead sometimes? - 12/28/12 01:32 PM

Quote:
And all of this went down while the tech was there? About 15 minutes to remove/replace the action and repair the whippen pin… hook up the pedals….
Simple to call forward the next appointment and be a bit late.


In all fairness , he did stay 20 minutes past the time I had scheduled for the tuning. He's a very well respected tech and I have confidence he will resolve this problem, I couldn't say how he tuned the dead keys except that they only refuse to sound at random moments about every 6-7 times struck (don't stick at all) and of course refused any misbehavior the second he stepped in the room except for the one time. FWIW he did this initial assessment gratis and the second visit will be covered under guarantee by seller.

Nevertheless thanks for your responses.
Posted by: Jerry Groot RPT

Re: What would cause a key to be dead sometimes? - 12/28/12 01:40 PM

We have all encountered that sort of luck from time to time. Sort of like going to the dentist with a tooth ache and when you get there, it's gone however, if it does it about every several strikes of the key and it did it while he was there, it should have been observed while it was dead to ascertain what was causing the stickiness, if that were possible. And, if it continues to stick after 6 or 7 strikes of the key, it should be able to be found. From the description of what he did, I would say he was guessing as to what the cause was.

Although, in his favor, sometimes, once it is unstuck, the note can refuse to stick again too. It can be frustrating occasionally but not impossible..
Posted by: TunerJeff

Re: What would cause a key to be dead sometimes? - 12/28/12 01:49 PM

Concur!

When you KNOW which notes are failing, it just isn't that hard to determine where the problem is, is it???

My method for determining the problem is to try and isolate the parts and lift everything seperately.

1. Hold the back of the key down.
Push the hammer forward and release. Slow?
Fix it.

2. Hold the back of the key down. Push the hammer slightly forward.
Lift the whippen away from the key and release. Slow?
Fix it.

3. Rotate the hammer slightly forward.
Press on the jack and release. Slow?
Fix it.

4. Just press the jack and release.
Does it re-set properly?
Does it hang short of fully under the hammerbutt?
By a little or a lot?
Fix by re-setting capstan.

5. Lift the whippen and hammer clear of the key.
Check the key travel through full range of motion.
Lift slightly and release; does it move easily? All good? Slow?
Fix it.

Basically; try and check each moving part as a seperate motion, without the weight or springs of anything else that might 'help' the part move.

My guess would be insufficient lost-motion on the jack. Yamaha actually suggests zero-clearance, but not lifting the hammer. This usually works fine, but maybe zero, in this case, is actually a little too 'zero' and the jack is binding. I'd back the capstan down, and then crank it back in carefully.

Second guess would be a slow jack; and re-pin that puppy. Possibly the jack-spring is not strong enough...but that's not a typical Yamaha issue.

Third would be the whippen; and re-pin. But, whippens are fairly robust pieces of wood...lots of weight...and it would take a really tight pin to make that the problem. Not a typical Yamaha issue, either.

Maybe a little higher on that list should be checking the key's balance-rail opening. Yamahas do occasionally have overly tight binding on the balance rail-pin, coming from the factory just a 'smidge too tight. But, the key would not re-set to 100% when released...it would be just a tick lower than the surrounding keys. You'd find that issue when checking the key motion as described above. Or, by lifting and releasing the key, by itself; a tiny lift of the key and release...it should fall back into place. If not...the keybushings are tight, or the balance-rail opening needs attention. I have a lot of Yamaha clients (schools and private), and easing the balance-rail opening or easing a few keys is a typical in 'young' pianos. I prefer this (...too tight) to having it loose right out of the box, personally. To me, it just means they are aiming for a precise and tight action and keys. Good!

I am surprised, as Ryan and Dan are, that the problem did not get first priority from the tuner/tech. Notes not working are number one for me, too. Especially when I know exactly which keys are the problem!

Good grief!
Posted by: Withindale

Re: What would cause a key to be dead sometimes? - 12/28/12 01:59 PM

Originally Posted By: Ragdoll
FWIW he did this initial assessment gratis and the second visit will be covered under guarantee by seller.

It would do no harm to check the other 86 keys during the second visit just in case they could be suffering from a mild form of the same problem(s).
Posted by: Ragdoll

Re: What would cause a key to be dead sometimes? - 12/28/12 02:05 PM

Quote:
Although, in his favor, sometimes, once it is unstuck, the note can refuse to stick again too. It can be frustrating occasionally but not impossible..

wow wow wow Is this some kind of code I don't get? ha It does not stick down and returns fully, will sound if pressed immediately again, may not be silent for the next 6 or seven time when pressed and then randomly go silent again. Unless stuck means something different than my interpretaton of "stuck". I apologize if I have not described this problem correctly because I don't understand a lot of the terminology used here. blush I feel like I'm being a pest now. I will print these responses and show them to Ray next visit as I would not presume to tell him his job. Again, thanks everyone.
Posted by: Ragdoll

Re: What would cause a key to be dead sometimes? - 01/17/13 12:00 PM

Sorry for dredging this topic up again butt... My piano tech just left and I'm so happy I could almost cry. I'm not sure of all that he did but the major part of his time was spent adjusting the lost motion throughout the whole key board. Also used something called ProTek on the keys in the troublesome octave.

The touch feels so different now and the dead key(s) issue is solved. Just in case I insulted anyone in my last post on this subject... Sorry, I was sooooooo frustrated trying to explain the problem, I was kinda snarky I guess. blush All told about an hour's work.

Doin the Snoopy Happy Dance.