roger2
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MODE & Loudness (Frequency & Level) switches
These are the three sealed or semi-sealed switches on the right side of the control board. Normally would probably leave these alone, but the MODE switch was acting up so something had to be done.
In the video linked below, the guy has melted holes in the clear plastic shields around these switches to provide entry points for Deoxit. This starts at 14:14. The whole video is informative and entertaining, well worth watching. Wonder if the videographer is an AK member ??
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwij6a3puMTVAhXm64MKHTbbAmMQtwIIKDAA&url=https://www.youtube.com/watch?v=WonSXuOnTtU&usg=AFQjCNHjqC46ZczkAo_p6I2JTfOQKE_65w
Anyway, I opened up the control board on my KA-7100, which has two of these switches, and practiced my technique on it prior to working on the KA-8100 switches. I used a punch from an inexpensive set of four from Walmart. The tool needs to be the right diameter, not too thin or thick. Heated it up in the flame of my gas kitchen stove and carefully melted a hole in the plastic a little at a time.
The construction of these switches is such that there is a wafer inside the switch about in the middle. On one side of the wafer, closer to the PCB, are the switch contacts. On the other side of the wafer is an air space. In the video, the holes were melted into the inner portion of the switch where the contacts are. But when I attempted that on my KA-7100 switches, the punch was pushing melted plastic inward, towards the contacts. So I tried putting the hole on the other side of the wafer, away from the contacts. That worked well as the Deoxit D5 spray went everywhere inside the switch regardless of where the hole was situated.
After a couple sprays, the D5 could be seen through the clear plastic partially filling up the insides of the switches. After working the switches through their range of motion about 50 times, I then sprayed compressed air (canned) into the same hole. The air flushed out most of the liquid nicely. I cleaned up the mess with IPA and repeated the process with Deoxit Gold and another air flush and cleaning, then waited overnight before powering up.
I never got any of the holes large enough to insert the little red Deoxit tube inside the switches. But I was able to press the tube sorta-part-way into the outer lip of the hole, enough to get the fluid (or air) inside. I did a total of five switches and all went well! The one switch on the KA-8100 that had been misbehaving worked fine after this treatment.
EDIT: Two things I would like to add here...
First, in regards to the video linked above, when I say that it is informative, entertaining and worth watching, to me it was all of those things. But I am not suggesting or implying that every method or action in that video should be followed exactly. Information there is presented in a coherent and understandable way, which I find to be a rare thing on youtube. And it is about KA-8100, so I thought I would add the link to this thread for whatever it may be worth to readers. Each person should, hopefully, assess what is presented and decide for themselves if anything might be worth adding to their own processes. Same thing with any information presented in this thread.
And the second thing that I would like to add to this post is that melting holes in the plastic cover of switches, as I have done here, is a risky maneuver and there is definite risk of a negative outcome. I am documenting one possible solution to a problem. I am not advocating that anyone else attempt this, especially if you feel uncertain about doing so.
In my case, I actually have past experience with doing something similar. Admittedly, it is highly unusual experience most likely. When I was a kid my Father and I were into slot car racing. I was young and he did most of the work on the cars. There was a certain Revell plastic slot car chassis that we "modified" so that a popular motor type would fit into that chassis. This modification procedure involved open flames (stove), kitchen knives, and melting/cutting that plastic chassis in just a certain way. My dad came up with this of course, but I got to be quite good at it.
Thus, the process as suggested in that video did not intimidate or put me off, indeed I had confidence going in that this method would work for me. As with anything, YMMV
These are the three sealed or semi-sealed switches on the right side of the control board. Normally would probably leave these alone, but the MODE switch was acting up so something had to be done.
In the video linked below, the guy has melted holes in the clear plastic shields around these switches to provide entry points for Deoxit. This starts at 14:14. The whole video is informative and entertaining, well worth watching. Wonder if the videographer is an AK member ??
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwij6a3puMTVAhXm64MKHTbbAmMQtwIIKDAA&url=https://www.youtube.com/watch?v=WonSXuOnTtU&usg=AFQjCNHjqC46ZczkAo_p6I2JTfOQKE_65w
Anyway, I opened up the control board on my KA-7100, which has two of these switches, and practiced my technique on it prior to working on the KA-8100 switches. I used a punch from an inexpensive set of four from Walmart. The tool needs to be the right diameter, not too thin or thick. Heated it up in the flame of my gas kitchen stove and carefully melted a hole in the plastic a little at a time.
The construction of these switches is such that there is a wafer inside the switch about in the middle. On one side of the wafer, closer to the PCB, are the switch contacts. On the other side of the wafer is an air space. In the video, the holes were melted into the inner portion of the switch where the contacts are. But when I attempted that on my KA-7100 switches, the punch was pushing melted plastic inward, towards the contacts. So I tried putting the hole on the other side of the wafer, away from the contacts. That worked well as the Deoxit D5 spray went everywhere inside the switch regardless of where the hole was situated.
After a couple sprays, the D5 could be seen through the clear plastic partially filling up the insides of the switches. After working the switches through their range of motion about 50 times, I then sprayed compressed air (canned) into the same hole. The air flushed out most of the liquid nicely. I cleaned up the mess with IPA and repeated the process with Deoxit Gold and another air flush and cleaning, then waited overnight before powering up.
I never got any of the holes large enough to insert the little red Deoxit tube inside the switches. But I was able to press the tube sorta-part-way into the outer lip of the hole, enough to get the fluid (or air) inside. I did a total of five switches and all went well! The one switch on the KA-8100 that had been misbehaving worked fine after this treatment.
EDIT: Two things I would like to add here...
First, in regards to the video linked above, when I say that it is informative, entertaining and worth watching, to me it was all of those things. But I am not suggesting or implying that every method or action in that video should be followed exactly. Information there is presented in a coherent and understandable way, which I find to be a rare thing on youtube. And it is about KA-8100, so I thought I would add the link to this thread for whatever it may be worth to readers. Each person should, hopefully, assess what is presented and decide for themselves if anything might be worth adding to their own processes. Same thing with any information presented in this thread.
And the second thing that I would like to add to this post is that melting holes in the plastic cover of switches, as I have done here, is a risky maneuver and there is definite risk of a negative outcome. I am documenting one possible solution to a problem. I am not advocating that anyone else attempt this, especially if you feel uncertain about doing so.
In my case, I actually have past experience with doing something similar. Admittedly, it is highly unusual experience most likely. When I was a kid my Father and I were into slot car racing. I was young and he did most of the work on the cars. There was a certain Revell plastic slot car chassis that we "modified" so that a popular motor type would fit into that chassis. This modification procedure involved open flames (stove), kitchen knives, and melting/cutting that plastic chassis in just a certain way. My dad came up with this of course, but I got to be quite good at it.
Thus, the process as suggested in that video did not intimidate or put me off, indeed I had confidence going in that this method would work for me. As with anything, YMMV
Last edited:
's... every one of those was noticed and appreciated 
