LKS 250 - Keys not working

[Bebe1980]

Hi,

 

the keys C1 to G1 on our LKS250 are not working - anyone know what the problem might be and whether there might be an easy fix ?

 

Thank you

 

ps. I tried to ask this question before but just got pending approval

 

Is there something I need to do to get my posts working ???

Edited March 6 by Bebe1980

[Brad Saucier]

Let's try a reset.  Press function>initialize>enter>yes.  After it restarted, try the keys.  

[Chas]

Out of curiosity, has your LK-S ever been opened? Did you buy it new or used?

 

The reason I ask is that a few years ago I had a similar problem with my XW-G1. A section of keys would suddenly not work, sometimes they would start working again. When they were not working, I hooked up another keyboard and found that everything worked fine over MIDI. I also tried factory resets and everything, the problem seemed to occur randomly. One day the section of keys stopped working again so I took my G1 apart. Instantly I found the issue - the keyboard ribbon connector was caught between one of the case screw posts and had a screw going through it! It appeared that the screw was (mostly) actually acting as the connector between a pierced wire in the ribbon cable.. I isolated the wire in the cable that had been pierced and spliced in a piece of new wired to bridge the damaged area. It's worked fine ever since.

 

I bought my G1 online, advertised as an ex floor model, though I wonder now if it was actually a return? No idea whether it came from the factory with a screw through the ribbon cable, but at least it's fixed and fully working again. 

[Chas]

22 hours ago, Bebe1980 said:

ps. I tried to ask this question before but just got pending approval

 

Is there something I need to do to get my posts working ???

 

As you are a new user with no previous posts, it's just a security check to ensure that you aren't a spammer or a bot. Once you've made and had accepted a number of posts, then you'll be able to post freely without needing approval. 👍

[Bebe1980]

8 hours ago, Chas said:

 

As you are a new user with no previous posts, it's just a security check to ensure that you aren't a spammer or a bot. Once you've made and had accepted a number of posts, then you'll be able to post freely without needing approval. 👍

Thanks :)

[Bebe1980]

20 hours ago, Brad Saucier said:

Let's try a reset.  Press function>initialize>enter>yes.  After it restarted, try the keys.  

 

Thanks I just tried that - still the same .

[Bebe1980]

9 hours ago, Chas said:

Out of curiosity, has your LK-S ever been opened? Did you buy it new or used?

 

The reason I ask is that a few years ago I had a similar problem with my XW-G1. A section of keys would suddenly not work, sometimes they would start working again. When they were not working, I hooked up another keyboard and found that everything worked fine over MIDI. I also tried factory resets and everything, the problem seemed to occur randomly. One day the section of keys stopped working again so I took my G1 apart. Instantly I found the issue - the keyboard ribbon connector was caught between one of the case screw posts and had a screw going through it! It appeared that the screw was (mostly) actually acting as the connector between a pierced wire in the ribbon cable.. I isolated the wire in the cable that had been pierced and spliced in a piece of new wired to bridge the damaged area. It's worked fine ever since.

 

I bought my G1 online, advertised as an ex floor model, though I wonder now if it was actually a return? No idea whether it came from the factory with a screw through the ribbon cable, but at least it's fixed and fully working again. 

 

Hello - thanks - no never taken apart and bought it new for my kids who have probably been a bit rough with it I think...

 

 

[Bebe1980]

By the way the lights don't work either for that section of the keyboard - so it's not just the sound.

 

I use the transpose function to wind it down -12 when I use it for practice or learning something new from the pc - so it's not the end of the world but would be nice to fix it.

[Chas]

9 hours ago, Bebe1980 said:

By the way the lights don't work either for that section of the keyboard - so it's not just the sound.

 

I use the transpose function to wind it down -12 when I use it for practice or learning something new from the pc - so it's not the end of the world but would be nice to fix it.

 

If the the sound AND the lights aren't working for those keys, that does seem to suggest it's more of a physical hardware issue.

 

To try and isolate the problem, connect the LK-S to a USB MIDI device that you can use to send MIDI data to it. A tablet with the free Casio Chordana Play app will do the trick, or a laptop with a MIDI player. Then send/ play MIDI from the tablet/ computer to the LK-S and see if the same group of keys are unresponsive. If the problem keys play and light up over MIDI, then the problem is likely with the physical keyboard. If the same group of keys still do not light up or play, then the problem is likely within the internal sound engine of the LK-S. See the video below for how you can use your LK-S with the Chordana Play app.

 

Alternatively, ensure that key lighting mode is "ON" (see page EN-8 of the User Guide), and then play one of the built in songs (see page EN-17 of the User Guide). See if the problem keys light up and play that way. If they do, then that would point to an issue with the physical keyboard itself.

Hope this helps!

 

 

 

[Bebe1980]

1 hour ago, Chas said:

 

If the the sound AND the lights aren't working for those keys, that does seem to suggest it's more of a physical hardware issue.

 

To try and isolate the problem, connect the LK-S to a USB MIDI device that you can use to send MIDI data to it. A tablet with the free Casio Chordana Play app will do the trick, or a laptop with a MIDI player. Then send/ play MIDI from the tablet/ computer to the LK-S and see if the same group of keys are unresponsive. If the problem keys play and light up over MIDI, then the problem is likely with the physical keyboard. If the same group of keys still do not light up or play, then the problem is likely within the internal sound engine of the LK-S. See the video below for how you can use your LK-S with the Chordana Play app.

 

Alternatively, ensure that key lighting mode is "ON" (see page EN-8 of the User Guide), and then play one of the built in songs (see page EN-17 of the User Guide). See if the problem keys light up and play that way. If they do, then that would point to an issue with the physical keyboard itself.

Hope this helps!

 

 

 

OK thanks - I'll give it a try

[Bebe1980]

Update:

 

When I play an internal song the keys light up and the sound comes out

 

I tried the midi - same thing, no signals going from the keys C1 to G1

 

Couldn't find any midi files on Chordana so I played Danny boy from Chordana app and the keys light up and work

 

So that means?

 

It's to do with the physical keyboard - perhaps I should open it up and have a look -  maybe take a pic or two to share ?

 

 

[Chas]

Just to confirm from your post, when you play an internal song all the keys (including the problematic keys) light up and those notes produce sound?

 

And when you said you tried MIDI, do you mean send MIDI from LK-S keyboard to a MIDI recorder/ instrument? 

 

Plus, when you used the Chordana app to send Danny Boy to the LK-S, all the keys (including the problematic keys) light and produce sound?

If all the above is correct, then almost certainly there is a physical issue with the keyboard in your LK-S. It could be that something was spilt into the keybed and the contacts for those non functioning keys have been contaminated, or a connector might be loose/ damaged/ dislodged.

If you have some minor experience with electronics and taking electric things apart, have a look inside and see if there is something obviously amiss. If you are not familiar with taking apart electronic devices, best have someone more experience do this as electronic components can be easily damaged by inexperienced probing.

Lastly, how old is your LK-S? Is it still under warranty? If so, you could take it to an authorized Casio dealer and let them deal with it.

Let us know how you get on, and hopefully it will be an easy fix.

 

20 hours ago, Bebe1980 said:

Update:

 

When I play an internal song the keys light up and the sound comes out

 

I tried the midi - same thing, no signals going from the keys C1 to G1

 

Couldn't find any midi files on Chordana so I played Danny boy from Chordana app and the keys light up and work

 

So that means?

 

It's to do with the physical keyboard - perhaps I should open it up and have a look -  maybe take a pic or two to share ?

 

 

 

[Bebe1980]

2 hours ago, Chas said:

Just to confirm from your post, when you play an internal song all the keys (including the problematic keys) light up and those notes produce sound?

 

And when you said you tried MIDI, do you mean send MIDI from LK-S keyboard to a MIDI recorder/ instrument? 

 

Plus, when you used the Chordana app to send Danny Boy to the LK-S, all the keys (including the problematic keys) light and produce sound?

If all the above is correct, then almost certainly there is a physical issue with the keyboard in your LK-S. It could be that something was spilt into the keybed and the contacts for those non functioning keys have been contaminated, or a connector might be loose/ damaged/ dislodged.

If you have some minor experience with electronics and taking electric things apart, have a look inside and see if there is something obviously amiss. If you are not familiar with taking apart electronic devices, best have someone more experience do this as electronic components can be easily damaged by inexperienced probing.

Lastly, how old is your LK-S? Is it still under warranty? If so, you could take it to an authorized Casio dealer and let them deal with it.

Let us know how you get on, and hopefully it will be an easy fix.

 

 

OK I'll take it apart later - I suspect the boy, who can be very heavy handed, has dislodged the contact thingies at some time - used to bang on it quite a lot

 

[Bebe1980]

OK... not sure this will work but here are the url to the images

 

https://imgur.com/UqgJ1sh
https://imgur.com/uaf8c1K
https://imgur.com/fAJDMd6
https://imgur.com/wpaYFyg
https://imgur.com/dFQRwDf
https://imgur.com/VTFwGd9

 

I took it apart - 19 screws for the case and 8 for the plastic keys...

 

It's quite easy - just hold it together when it's unscrewed, turn it over and lift the top and bottom apart - starting with the handle... then rest the top against some pillows or something.

 

I couldn't see any damage from liquid etc. - perhaps it's on the other side - underneath - I gave it a little dust and put it back together - still works. I didn't want to take off the all the keys and look at the other side as I doubt I'd know the difference!

 

So I couldn't fix it.

 

Guess I'll either need to buy a whole new key contact board to plug into the control board - or maybe send it for repair.

 

I did disconnect the main ribbon cable from the control board to the key contact board and reconnect it but that didn't change anything.

 

 

 

 

Edited March 9 by Bebe1980
Found out more info

[Bebe1980]

I've had a look on CASIOPART and discovered:

 

https://imgur.com/1Yv1Y9P

 

about 5 PCB's that could be the right one - anyone suggest which one it is ?

 

My guess is: Casio 10605038 PCB UNIT/KYD1 @ $ 100.71

 

Numbers I can see on my photo are:

 

PWR NAGL KYD1 RJM511732-001V0 N40A35B5/A30C5/C7A3/C7

 

N40A35B5/A30C5/C7A3/C7 - This number comes up in google as a part number but I cannot find an image to match it against !

 

 

 

[Chas]

@Bebe1980 - Looking at this picture of your LK-S250, that is a considerable amount of dust inside the keyboard. If quantities of that has made it's way underneath the rubber key sensor strips, it could be interfering with the carbon pads that make contact with the circuit board and stopping them from triggering.  If you haven't already, you should be able to lift off the rubber contact strip  to make sure it's clean underneath, both the carbon pads and also the circuit traces. 

 

 

 

 

 

 

Another test you could try is to swap over the rubber key sensor strips from a known working area of the keyboard to the non working area. If you look at your picture below, they are in strips of 12 sensors. 

 

 

The idea here is to see if the problem moves with with rubber strips. If it does, then you've located the issue to the rubber strips. Ensure that the circuit board underneath the sensors is clean before you swap them over.

If the problem keys remain in the same place, and you've ensured that all the contact areas are clean, then the issue is most likely a fault with the keyboard matrix or the ribbons connecting the keyboard to the mainboard. 

 

 

 

And if these are the ribbons from the keyboard assembly:

 

 

Ensure that they are seating correctly in their sockets. Also look for any obvious breakages, though it's unlikely the ribbons would break if the LK-S has neve been opened before.


Lastly, if you have a multimeter, you could try continuity checking each key sensor on the circuit board to see if it's completing the circuit when each key sensor is pressed. You should be able to locate a common ground for the keyboard sensor circuit, then locate the trace for each of the problem keys. See if the multimeter picks it up that way. If it does, then the problem lies deeper on one of the main boards. If you still can't pick up any key presses for the non responsive keys this way, then the damage likely lies in the key bed assembly somewhere.

I would check the above before thinking about replacing any boards. I can't help you with which boards are which in the picture in you last post, and ideally you would need to get hold of a Service Manual that would identify what board does what. Or you could contact the company selling them and ask them what each board does. Saying that, two were specific to the LK-S, so those would almost certainly be specific to the key lighting section as none of the other Casiotone models have lighted keys.

 

 

Hope this helps!  

Edited March 11 by Chas

[Bebe1980]

3 hours ago, Chas said:

@Bebe1980 - Looking at this picture of your LK-S250, that is a considerable amount of dust inside the keyboard. If quantities of that has made it's way underneath the rubber key sensor strips, it could be interfering with the carbon pads that make contact with the circuit board and stopping them from triggering.  If you haven't already, you should be able to lift off the rubber contact strip  to make sure it's clean underneath, both the carbon pads and also the circuit traces. 

 

 

 

 

 

 

Another test you could try is to swap over the rubber key sensor strips from a known working area of the keyboard to the non working area. If you look at your picture below, they are in strips of 12 sensors. 

 

 

The idea here is to see if the problem moves with with rubber strips. If it does, then you've located the issue to the rubber strips. Ensure that the circuit board underneath the sensors is clean before you swap them over.

If the problem keys remain in the same place, and you've ensured that all the contact areas are clean, then the issue is most likely a fault with the keyboard matrix or the ribbons connecting the keyboard to the mainboard. 

 

 

 

And if these are the ribbons from the keyboard assembly:

 

 

Ensure that they are seating correctly in their sockets. Also look for any obvious breakages, though it's unlikely the ribbons would break if the LK-S has neve been opened before.


Lastly, if you have a multimeter, you could try continuity checking each key sensor on the circuit board to see if it's completing the circuit when each key sensor is pressed. You should be able to locate a common ground for the keyboard sensor circuit, then locate the trace for each of the problem keys. See if the multimeter picks it up that way. If it does, then the problem lies deeper on one of the main boards. If you still can't pick up any key presses for the non responsive keys this way, then the damage likely lies in the key bed assembly somewhere.

I would check the above before thinking about replacing any boards. I can't help you with which boards are which in the picture in you last post, and ideally you would need to get hold of a Service Manual that would identify what board does what. Or you could contact the company selling them and ask them what each board does. Saying that, two were specific to the LK-S, so those would almost certainly be specific to the key lighting section as none of the other Casiotone models have lighted keys.

 

 

Hope this helps!  

 

Thanks Chas,  I'm sure you're right but not being the owner of a multimeter - think I'll just leave it as it is