Hello,
Recently just purchased a used radio from a local racer. I'm having issues with the enter button working like half the time, sometimes you have to press it really hard, sometimes it works, and sometimes it just doesn't work at all. My friend suggested, since the radio looked pretty dusty in the wheel, that taking a can of air to the scroll wheel might clear out dust that is stuck in there. I'm going to try that, but does anyone have any other suggestions?
Thanks

A can of air is a good start and you should try that first, but you made need to use some electronics cleaner on the scroll wheel to really clean out what is stopping it from working. You'll be able to get better access and do a better job cleaning if you take apart the radio.

Yeah, that's what I was thinking. I just don't know if I want to try to take apart the radio - don't want to mess anything up. I have taken apart an MT-S and it went back together fine but the M12 is probably more complicated. I know you can replace all the internals but I don't want to go to that yet. I will just have to be careful and take lots of pictures.

I was race on dirt too and was curious to see what would be involved to clean the enter wheel on my M12S. It really isn't as daunting as it looks, because the 'nose piece' of the radio comes off with just 4 screws and gives access to the enter wheel. You could easily disconnect the wire harness to completely remove this piece and its circuit board from the main radio.

Thank you so much! That is super helpful. I will try it when I get home.

Ive heard this issue b4 with m12 most just replace the entire scroll knob

Is there a place I can find it or should I contact Sanwa?

I fixed a friends M12S a few weeks ago with the same issue. He tried contacting both Sanwa and Serpent (US Distributor) with no luck.

Fixing it was not overly difficult and can be fixed in about 15 minutes. Using a meter, check that you get a closed circuit when you press the switch down. In my case, the switch remained opened indicating the switch was bad.

Remove the four screws that mushroomed showed. There are two additional screws that hold the circuit board to that cover piece, take those off also.

Micro switch that was not working.



I unsoldered the switch from the board, i found however this was NOT required. Using a your fingernail or a small screwdriver, you can carefully pry back the two plastic tabs that hold this small metal switch cover off.



You can see the contacts of the switch were very dirty, so it was not making a good connection. No pictures of this part, but i used a brass wire brush to clean the contacts of the switch housing and the spring / bridge contact. I then reassembled the switch. The plastic tabs holding the cover piece were slightly deformed from disassembly, so i used a VERY small dot of CA glue to make sure the cover does not come off.



Soldered back on (Again, you can do the above without removing the micro switch from the board).

Thank you so much. Compressed air worked for now but I will try this in the future if it happens again.