How to fix a broken key on an old yahmaha?

[Mongoo]

My friend has an old yamaha. It's like a clavenet but older, like from the mid/late 90's. It's big, comes with a nice stand and pedals built in.

Anyways, he..um.. broke one of the keys, so now when you play the 2nd A below middle C It plays the note as if your pounding on it. All of the other keys seem fine, but you run across that A key and you'll notice it without question.

Does anyone know how to fix this or about how much it will cost?

Thanks,

Mongoo

 

[ssscientist]

like from the mid/late 90's

Are you talking, like, the ancient 1890's?

Or just the good old days of the 1990's?










Either way, is this an acoustic or electric 'board?


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[Mongoo]

...

It's from the mid late 1990's, and it is a yamaha weighted 88 key electric digital piano. As far as I know it is just one bad key, but I don't know how to check if the other keys where otherwise more mildly effected. My friend got drunk one night and decided he'd hit his keyboard with his fists to add expression to his discenent playing.

Can it be fixed?

 

[ssscientist]

Can it be fixed?

Sure.

It's almost certainly a sensor under the key. The first thing to determine is whether or not, as you say, keys around it are affected. Then unplug the keyboard and either find a way to crack into it and see what kind of sensors it uses, then go out on the web and find a replacement, then take the old one out and solder the new one in.

Or you could take it to The Good Guys in St.Paul and have them do it.


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[SonicAlbert]

It might be as simple as some dirt stuck under the key interfering with the sensor. Try blowing out under the key with a can of compressed air. It might work, or it might not.

Either a good cleaning will do it, or there needs to be some repair made. In both cases you'll probably need to take the keyboard in to a repair shop.

 

[The Green Hornet]

Yo Mon:

Somewhere in Minn. There must be a seller of Yamaha keyboards or pianos. In either case, if you can't figure out how to fix it yourself, call and ask if they can.

Here, we have a Keyboard World that "could" do repairs on either of my keyboards if necessary which I hope WON'T BE NECESSARY.

This way, using a hometown repair service, your friend can avoid paying the "heavy" shipping charges.

BTW: Only Victor Borge can get away using his fists for accent [when he was alive] as he could afford the repairs.

 

[dementedchord]

ok.... ready???? the sensors that yamama uses are a strip of rubber with 2 ridges of conducting material on it... they are pushed down onto the switchboard by the key and incounter 2 "dots" of the same conductor... the problem then is one of 2 things... 1 the strip and/or dots are dirty and should be cleaned with alcohol... get the full strength shit from a paint store... donot under any circumstances use rubbing... or WD40... or cleaner lube like you use for pots... 2nd possibility the strips sometimes get cut by the key... only thing to do here is if your lucky you can reverse the stripp (end for end) and the cut wont fall on another note... or replace the damn thing... the hard part there is copping the part as alotta places dont want to sell parts....

 

[Cazzbar]

oo shame this thread isn't about a broken key on a Roland A90 one of mine is currently sitting perma-pressed down after our last gig... paid about £130 to fix it last time one broke (all labour charges) I took all the screws out of the heavy beast yet nothing budged and had that feeling I'll never get it back together again anyway so I took it to the shop.

If I take it back again I would have paid more to keep my piano on the road than my car

 

[dementedchord]

been awhile sisnce i did one of those... but what your probably experiencing has to do with a weight system used for the key return... could be the frame that it sits in as well...

 

[dgatwood]

My friend has an old yamaha. It's like a clavenet but older, like from the mid/late 90's. It's big, comes with a nice stand and pedals built in.

Anyways, he..um.. broke one of the keys, so now when you play the 2nd A below middle C It plays the note as if your pounding on it. All of the other keys seem fine, but you run across that A key and you'll notice it without question.

Are you saying that the key falls too easily like the weight came off, or are you saying that it plays loudly like you slammed the key down? The former is easy. Reattach whatever came off. The latter... well....

The way velocity sensitivity works is that two switches close in sequence as the key falls. The difference in time between when one closes and the second one closes tells the speed of the key, which in turn is translated into volume. Depending on how the circuit is wired, if the first switch doesn't make contact before the second one closes, it might interpret the velocity as infinity, so the effective volume is "as loud as possible".

Another possible way the circuit could interpret things is that if a short causes the second contact to be constantly closed and then the first one closes, the time between the first and second contacts is zero, which would be very loud. I'm not sure which way their velocity sensitivity circuitry works, but it is likely one of those two.

Another possibility is that some reed switch or something has shifted so that it closes much earlier than it is supposed to, but judging from the way folks have described their switching system, that doesn't seem too likely. My guess is that some piece of metal came off and is shorting the second set of contacts, but that's just a gut reaction.

 

[Anthony]

Does anyone know how to fix this or about how much it will cost? Thanks,Mongoo

Someone had partly similar problem a few months ago.

Read my second post, at least to know, what you shouldn't do on your own and benefit the same conclusion found here

P.S. Ssscientist and everyone, I think I forgot to wish everyone here all the best for 2007.

 

[person346]

Same for Alesis Quadrasynth 4?

ok.... ready???? the sensors that yamama uses are a strip of rubber with 2 ridges of conducting material on it... they are pushed down onto the switchboard by the key and incounter 2 "dots" of the same conductor... the problem then is one of 2 things... 1 the strip and/or dots are dirty and should be cleaned with alcohol... get the full strength shit from a paint store... donot under any circumstances use rubbing... or WD40... or cleaner lube like you use for pots... 2nd possibility the strips sometimes get cut by the key... only thing to do here is if your lucky you can reverse the stripp (end for end) and the cut wont fall on another note... or replace the damn thing... the hard part there is copping the part as alotta places dont want to sell parts....

Do you know if this would be the same solution for silent keys on an Alesis Quadrasynth 4?

 

[dementedchord]

Do you know if this would be the same solution for silent keys on an Alesis Quadrasynth 4?

i never worked on one of those but it wouldn't surprise me.... if it's silent whats probably happening is.... as someone mentioned earlier there's 2 switches for each key... the diff in timing gives you your velocity... so in your case it's most likely getting either none of the switches or just the first and interpreting it as an infinately soft attack...