WK-3700 Key Problem

[RustySkull]

Hey everyone, I'm new to this forum but also new to Casio Keyboards!

 

I have bought a WK-3700 but shortly after playing it for the first time some of the keys became "Stuck" the actual keys don't physically get stuck down but once pressed they don't play again and on the display they're shown as still being pressed? If you change piano type they reset but the same happens again. This must be a setting issue?

 

Things I've done to try and fix it:

Reset the System (no luck)

Reset Parameters (No luck)

Played with every setting in the manual (Still no luck) ...

 

I should point out that the other keys are set to pressure setting 3 so the volume is according to the amount of pressure applied but the four troublesome keys are not pressure sensitive.

 

I know I'm new and this is my first post but can any of you lot help me with this problem please? The really annoying thing is the keys they are playing up are the ones I need!

 

Thanks in advance

 

-Rusty.

[- T -]

Rusty

 

Under the keys are dimpled rubber strips.  Each strip typically provides a dimple under each key for one octave.  Inside each dimple is a carbonized disk or a peg, the bottom end of which has been carbonized.  When a key is pressed, the dimple is compressed until the carbonized disk or peg shorts together a set of electrical contacts on the circuit board under the rubber strip and turns on the tone oscillator for that key.  See the photos at:

 

http://www.bing.com/images/search?q=casio+keyboard+key+contact+repair+strips&qpvt=casio+keyboard+key+contact+repair+strips&qpvt=casio+keyboard+key+contact+repair+strips&qpvt=casio+keyboard+key+contact+repair+strips&FORM=IGRE

 

With age, the rubber strips begin to deteriorate and lose their resiliency, allowing the dimple to stay compressed and the tone to stay "on", even after the key is released.  Quite often, the afflicted key(s) will be a little lower than the surrounding non-afflicted keys when sighting the length of the keybed.  In the early stages of this condition, the collapsed dimples will sometimes return to their normal positions after a few hours or overnight, making it appear that the problem has gone away, but it soon returns after a few presses of the afflicted key(s).  When a key fails to produce a tone, that is normally an indication of dirty electrical contacts under the dimples.  This situation can usually be eliminated by removing the rubber strips, cleaning the contacts, and re-assembling everything, but once the rubber strips begin to deteriorate, about the only fix is to replace them.  This can be done by the user/owner, but it is quite involved mechanically, and is not for the technically faint of heart.  In those cases, it is best to send the keyboard to a repair center or just to retire it.  With the age of your WK-3700, a repair center repair would almost certainly exceed the worth of the keyboard, but I will offer this word of caution, depending upon your particular situation and relationship with the WK-3700.  Many former WK-3X00 owners sold their boards to help finance the cost of the newer models, and are now sorry for it, as there are several popular features of the older models that were not carried over into the newer units - popular tones, popular rhythms, ability to load and play tone and drum samples, etc.  Personally, I still depend on my 10 year old WK-3800 enough that, if it were to develop this condition, I would go to the trouble to repair it or to the expense of having it repaired if at all possible.  If you decide to repair your WK-3700, try a Bing or Google search on "Casio keyboard key contact repair strips" for more information.

 

[RustySkull]

20 hours ago, tnicoson said:

Rusty

 

Under the keys are dimpled rubber strips.  Each strip typically provides a dimple under each key for one octave.  Inside each dimple is a carbonized disk or a peg, the bottom end of which has been carbonized.  When a key is pressed, the dimple is compressed until the carbonized disk or peg shorts together a set of electrical contacts on the circuit board under the rubber strip and turns on the tone oscillator for that key.  See the photos at:

 

http://www.bing.com/images/search?q=casio+keyboard+key+contact+repair+strips&qpvt=casio+keyboard+key+contact+repair+strips&qpvt=casio+keyboard+key+contact+repair+strips&qpvt=casio+keyboard+key+contact+repair+strips&FORM=IGRE

 

With age, the rubber strips begin to deteriorate and lose their resiliency, allowing the dimple to stay compressed and the tone to stay "on", even after the key is released.  Quite often, the afflicted key(s) will be a little lower than the surrounding non-afflicted keys when sighting the length of the keybed.  In the early stages of this condition, the collapsed dimples will sometimes return to their normal positions after a few hours or overnight, making it appear that the problem has gone away, but it soon returns after a few presses of the afflicted key(s).  When a key fails to produce a tone, that is normally an indication of dirty electrical contacts under the dimples.  This situation can usually be eliminated by removing the rubber strips, cleaning the contacts, and re-assembling everything, but once the rubber strips begin to deteriorate, about the only fix is to replace them.  This can be done by the user/owner, but it is quite involved mechanically, and is not for the technically faint of heart.  In those cases, it is best to send the keyboard to a repair center or just to retire it.  With the age of your WK-3700, a repair center repair would almost certainly exceed the worth of the keyboard, but I will offer this word of caution, depending upon your particular situation and relationship with the WK-3700.  Many former WK-3X00 owners sold their boards to help finance the cost of the newer models, and are now sorry for it, as there are several popular features of the older models that were not carried over into the newer units - popular tones, popular rhythms, ability to load and play tone and drum samples, etc.  Personally, I still depend on my 10 year old WK-3800 enough that, if it were to develop this condition, I would go to the trouble to repair it or to the expense of having it repaired if at all possible.  If you decide to repair your WK-3700, try a Bing or Google search on "Casio keyboard key contact repair strips" for more information.

 

Hey tnicoson!!

 

Many thanks for your detailed reply!

I know a little about how the keys work and I've come across many things with the same rubber dimple and contact design for buttons in the past, luckily I rather enjoy fixing broken electrical items so now you've confirmed my original suspicions that it is a physical issue and not a setting I'll be fixing it myself. 

The thing is loads of people had told me it's a setting that you can adjust but what setting appeared to be unknown! Which is why I came to this forum thinking one of you is bound to know how to unset it lol. I don't mind having to take it apart because while I'm at it I'll replace all of the rubber's because I know from other things that they do perish. It's a similar design in the older iPhone's for the home button, I have fixed many of those in the past haha. 

 

Anyway thanks again!

 

P.S one question if you don't mind please? How old are the WK-3700's? There is a date on the box of 2005 is that right? What would you say they're worth now? I paid £50 for mine boxed too and to tell you the truth I thought I over paid :/

 

-Rusty.

 

 

[- T -]

Rusty

 

The WK-3700 was the immediate predecessor to the WK-3800.  The WK-3800 was released in 2006, so I would say that the date of 2005 on your WK-3700's box is an accurate manufacture date for it.  I purchased my WK-3800 new in December 2006 for $400 USD (308 GPB).  I think the WK-3700 originally sold for about the same amount.  There are currently three WK-3800's on Amazon for $350 USD (270 GPB).  Personally, I think this is very overly optimistic, but as I alluded to in my previous reply, the used WK-3X00 market is very strange.  They have an almost cult-like following, particularly for those using them for gigging or music production.  This is due to the fact that all of the WK-3X00 models shared some important traits throughout the entire model line - tones, rhythms, sampling, etc. many of which were omitted on the recent model releases.  Add to this the fact that the audio systems and speakers of the WK-3X00 models were designed more along the lines of boom-boxes, while those of the newer models are more closely related to precision studio monitors.  So, what would give you a resounding "boom" on a WK-3X00 model will now give you a brisk "thump" on the newer models.These differences have caused some very distinct divisions among CTK/WK fans - old versus new.  So it is understandable that a WK-3X00 fan, whose trusty keyboard has recently given up the ghost, is usually willing to pay considerably more for a used replacement that is in good condition than someone with just a casual general interest.  So, it is a bit difficult to say what a used WK-3X00 is really worth.  It all depends on the buyer's background and needs.

 

Good luck with your endeavors to repair your WK-3700.  I am sure it will be well worth it.

 

Regards,

 

Ted

 

[RustySkull]

21 hours ago, tnicoson said:

Good luck with your endeavors to repair your WK-3700.  I am sure it will be well worth it.

 

Regards,

 

Ted

 

Ahh I see, well thanks for your help Ted, I'm having real trouble finding a place that sells the strips but I'm sure I can come across some soon ;D

 

Rusty.

[HermX1]

Same thing happened to me back from 2011. Sometimes happen in the higher range keys and sometimes in the mid or the lower. Sometimes when some keys are pressed it sounds really load as if there's no touch response activated in those specific keys, also when keys are pressed once it will not sound again unless you power off/on the keyboard. Really annoying. I just gave up, i know could be a million things but let me tell you something guys i own a CTK750, been the only owner since bought it back 1995 and never a single issue, just using it again after years in the gig bag since the beginning of the week to replace the wk-3700 at the living room instrument and it works just perfect. I also own a Yamaha S90 (well that's a different animal).

 

After dealing so many years with Casio brand keyboards and other brands also, but mainly Casio, this is the first time i have a faulty product, to my limited knowledge and IMHO is the main circuit board, the CPU of this thing went wack.

[Jokeyman123]

Rusty-keep looking for the rubber strips. See if you can find strips that look identical and I mean identical that may not necessarily be Casio branded or identified as such. Even a slight variation in size would not work, believe me! And there are 2 carbon contacts-each one is a slightly different height-yep! The lower one as you look directly down from the front of the keyboard is a simple on/off contact. The upper one will contact milliseconds after the first-this controls velocity by comparing the time between the 2 carbon contacts hitting. Talk about brain salad surgery-If these are even slightly off or worn, strange things will happen!

 

Playing a PX575 regularly (same basic keyboard as yours with 88 piano keys, still am astounded at how good this instrument sounds and I've played everything,  I've edited sounds, created samples and even use the drawbar settings live-the organs and pianos sound as good as my PX350 and XW-P1 although I can hear the improvement in the PX350 acoustic pianos but not by much) I'd go ahead and try to repair it. Having done this with many keyboards old and new-be careful when you get the strips, do not contaminate the carbon contacts with anything! I learned this the hard way-any cleaners except for a plain damp towel free of lint will affect the conductivity of the carbon, these seem very sensitive to any contamination. There is a liquid conductive carbon based glue available on eBay-comes in a small container which does work for certain applications if you need that in an emergency-I've had mixed results with it where I needed to restore a few worn carbon contacts but it is better to replace an entire strip.

 

Having disassembled the XW-P1, PX350 and PX575, these use the dual contact boot design, not the single-which would be used in keyboards with no velocity sensitivity so I'm pretty sure the WK will have the same as mine. And looking at the above posted pictures you may be in luck that the WK uses the same design as many other keyboards. Fatar contact strips for example are used by Ensoniq, Kurzweill and many of the Studiologic and other controllers. Again, I've learned this from long experience and difficult restorations.There is a place called the Midi Store that sells some of these, also check the eBay listings and other keyboard parts suppliers online. I just spent weeks trying to find what I thought was an impossible set of strips for an old Edirol keyboard, until I stumbled upon them at-surprise-Roland's factory website, that had exactly what I needed! Who would have guessed! Your best bet is to get the Wk dissected, examine the strips carefully yourself, and go from that vantage point. You know what, there is something immensely satisfying about restoring your own instruments (especially if you succeed and don't turn it into a doorstop!) And watch out for the used contacts listed on eBay-do not buy these, they're potentially worse than what you have, you need new.

 

Just a couple of other useful tips-have one of those thin magnetic retrieval tools to grab any screws you might lose. I also use a bit of "poster putty" on the tips of my screwdrivers to secure screws in hard to reach places. And take pictures with whatever you have-phone camera, digital anything in case you forget where everything goes back!  Yes I used to do alot of car repair/mechanical work and apply the same principles on keyboards. A good monkey wrench and wrecking bar is good if all else fails as well as a good solid 5-pound sledgehammer. At least I can keep my trucks running in case I decide to just run over the entire keyboard with it as a last ditch final solution-I've been tempted!      

 

So try Casio, maybe they actually have these contact strips. And have a happy Thanksgiving. may you always have something to be grateful for!

[HermX1]

FOllowing up with this issue. My keyboard has been in a bag for the last 3 years, yesterday i decided to take a deeper look and I think the problem of this keyboard is the key contact board or the PCB ASSY/KY1-2M as per the service manual, deeper than that trying to understand the matrix it's probable a diode (1SS133T-77) which this two pieces part use 152 of it can be damaged. How many?  I don't know cause i need to understand the matrix first. I have to set of 8 notes each not closing the circuit that's why remain pressed in the screen, the lower 8 produce sound just one time and the upper 8 no sound at all. Those diodes are responsible for fast switching that's why they are there, basically is the job they do. 

 

I talked yesterday to PACPARTS and they sell the whole PCB ASSY/KY1-2M for $40 including shipping to my location which is fair to repair an almost 15 years old keyboard. I'm trying to get the diodes which are obsoletes but still available on ebay for $7 a pack of 5, I'm thinking about it or to get the whole PCB which I will need to weld the multiple pin connectors, Very bad this should be a connector part but it is what it is. 

 

I would like to know your thoughts on this as well and know if Rusty was able to solve the problem.

[Jokeyman123]

If you are familiar with a multimeter-a simple one will do-Google diode check and measure the diodes in question-isn't too hard if you are patient-diodes very rarely fail but are like little fuses so can blow. I would more strongly suspect oxidized or loose cable connectors/sockets-this is where I've run into failed/intermittent key problems. Even a tiny hairline crack in a solder connection can cause grief and the socket connectors flex over time and can crack or loosen.-I have had to check with powerful magnification to detect problems like this I've fixed. And these are repairable if you have a steady hand and some soldering skills. since this has been sitting-suspect oxidation in socket connections and check these. I just repaired a microKontrol that had an octave out-one solder trace in one pin (!) by one of the keyboard connectors was cracked-almost imperceptible without magnification, and this was the problem. Hit it with a pencil solder pen and problem solved. 

[HermX1]

Hi Jokeyman and thanks for your input.  So you think my diode theory might not be right? This is the strange thing here, when all this starts was around 2011 and the problem start intermittently, even months went by and it was working fine after the first incidents, then the period of continuous playing with no problem was shorter every time until it got permanently after switching on and play those specific notes. 

 

Also what caught my attention is the problem is repeated in just 8 chromatic notes lower range and upper. 

 

I will check again with a magnifier and post pics here for you to see, 4 eyes are better than 2.