Ultrasonic Cleaning for Apple II keyboard switches ???

[KLund1]

I have an early AII with a rev 0 keyboard. most of the keyboard switches are not working. A few on each row work so it is not the chips on the PCB. I tested them all with an Ohm meter, and marked which are not working. I have tried DeOxit D5 on one, pressed 50 times, no change. Electronics contact cleaner on another, pressed 50 times, no change. Compressed air on a third, and the the two after I already tested them,, pressed 50 times none worked. I submerged in ISO,, pressed 50 times, let dry, no change. I reflowed the solder joints, no change. I took one apart and polished all the copper inside and reassembled. That is NO EASY task. Start to finish took about 3 hours for one switch! Almost lost both tiny springs several times! And it still did not work. (not working I mean by testing with an ohm meter, not powering up the AII)

I saw people using an ultrasonics cleaner for their cherry key switches and it seemed to work great. 

Would that work for these switches?

Thoughts, ideas, suggestions ??

Thanks

[Baldrick]

It's one thing to get the water and cleaning solution INTO the switch and clean it ultrasonically.

 

It is quite another to get that water back OUT of the switch and dry it thoroughly.

 

I'd not recommend it.