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Kb37 Has Two "loud" Keys For Midi Events; Can I Open It To Clean?


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Hello,

 

My 2009 KB37 has two keys (low Ab and A) that always play midi tones as if the key was played hard. So pretty much every time I press the key at a given velocity it SOUNDS the midi patch as if I played it with force. Seems like a simple mechanical problem or perhaps a dirty connector on those keys?

 

Probably not under warranty and overall the keyboard is perfect for me but would rather not pay for repair if I can open it up and maybe clean something per your suggestions.

 

Please help if you can.

 

many thanks

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  • 3 months later...

Hi!

 

I have a similar issue, in that the what is basically ‘Middle E’ in terms of position on the keyboard started to play up, and was not velocity sensitive any more (the Loud Key problem you have described).  Then it went completely dead.  Given that it’s the middle E on the keyboard, this is a bit of an issue, and I’ve actually got out of the habit of using the keyboard, so the KB37 is a pretty massive sound card now.

To be fair, this is the only issue I’ve ever had with this hardware unit, and I have had it for a long, long time (it is one of the red TonePort models).

 

To answer your first question: Can it be opened for cleaning?  Yes - BUT - I don’t think it is design with user maintenance in mind.  You have to basically remove every screw that is in any way visible on the bottom of the chassis (there are a LOT, of several different sizes).  You also have to release the three-to-a-side Allen/Hex screws: these are the ones that sit at the top of the control surface.  I naively though t that they were the only thing holding the ‘clam shell’ casing together.  I was wrong.  These screws are difficult to work with as they have quite a shallow head, yo may need to hunt around for the right sized hex/Allen wrench, and they seem to be sealed with a strong dose of Loctite.  The challenge I found was getting enough pressure and torque onto the screw without stripping the head.  Like I say, I don’t think this sort of thing is supposed to be done at home, but like you, my unit is long out of warranty.

Obviously, you have take the control knobs of the various pots (this is easy - they do not have grub screws).  Then you have to ‘jiggle’ top of the clam shell and, eventually,  it does lift up, with the keyboard on the ‘lid’ as it were, and all the other electronics on the baseplate.  I have to say that the inside of my unit was pretty clean, which says a lot for the design quality of the device.  There was some dust and detritus in there, but nothing like what I had expected: also, lack of any fan or ventilation ports helps enormously.

 

Now the bad news: cleaning doesn’t seem to work.  I can’t see any obvious mechanical fault to blockage, so I’m wondering if it is a component failure?

 

The next step is to disassemble the keyboard itself, as it can be slid out from the upper lid of the casing.….

 

I’m not sure if that’s a step I want to take, as I early use the KB37 as a sound card and for guitar input - the MIDI keyboard was a nice-to-have bonus.

 

What to do, what to do…?

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OK - Curiosity got the better of me.  I took the keyboard apart.  I unscrewed the electronic keyboard panel for the physical keyboard.  There are a lot of screws here.  The interface between the physical key and the electronic sensor is a silicone rubber strip that looks a bit like a cross between an octopus’s tentacle and a ‘chocolate block’ electrical connector strip.  With the device open, I tried triggering directly on the rubber strip - after much prodding and poking, the Middle E key started triggering notes on Sylenth 1, but only at maximum velocity; with a bit more coaxing, it settled down.  I think the rubber had got a tiny bit puckered or skewed, or possibly there was some dirt inside.  I did not take the rubber strip off, as I truly thought that might be an irreversible step.  What I did do was pulled on the little ‘legs’ that hold the rubber strip onto the circuit board.

 

Putting the keyboard back together has to be done carefully - it is very easy to drip the holes on the circuit board.

 

Putting the whole unit  back together is even more fun, as you have to slide the keyboard in-and-under, as it were, then deal with aligning all the pot spindles, pressure switches, the VU meters, etc.

 

But hey! Everything works now, and should be good to go for another seven years?

 

I have a few photos if you’re interested - not a ‘tutorial’ by any means, but just to show which components and subassemblies I’m talking about.

 

Oh, and I had one screw left over: the hallmark of a successful DIY project.

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