I have a problematic old Datanetics keyboard on a (very) old Apple II Plus. I've replaced a couple of keyswitches and cleaned all the keys by injecting isopropanol alcohol into the keyswitches and "working" them for a while and that actually worked and I was able to properly use the keyboard. The Apple II Plus has since been in storage for some time and I took it out for a spin last night and then I experienced the same problems as before, some keys repeating and some you feel will not go back into position so quickly as it should after pressing it, so I'm basically back to square one :-(I do have a ultrasonic cleaner (with heat) that I that thought of using for this before. Is that a good idea? Anyone with experience from this? If so, please kindly explain the process (using warm water, temperature, detergent, duration, putting the whole keyswitch assembly in or disassembled (would be hard work if they keyswitch needs to be disassembled and assembled (at least a Datanetics one)), drying, lubing afterwards, alcohol afterwards etc. etc.).
The "angled" Datanetics keyswitch is pictured below, that is what I'm thinking of putting in the cleaner.
instead of IPA.
I have no experience of using ultrasonic cleaners.
I suspect there would be no benefit from ultrasonic cleaning a keyswitch. The surfaces you most want to clean from contamination are in physical contact already: dunking them in a tank of fluid will not squeeze between them and so cannot clean them.
If the switches are disassembled, they can be cleaned using the methods of watchmakers for small metal parts, which may include their methods for ultrasonic cleaning. You should note that small delicate objects (like switch plates or springs) are not placed directly in an ultrasonic bath. They use special fluids like L&R Mechanical Cleaner and #3 rinsing solution, in beakers within the ultrasonic tank. These cleaners are flammable and directly sonicating them is unsafe.
Vibrations seem to help stubborn keys. I don't have any experience with ultrasonic cleaners, but I have saved a lot of keys on ][ Plus keyswitches by simply soaking the key in soapy water for a couple of days and then placing the container on the clothes washer during a laundry cycle for agitation. It is a slow but pretty reliable process for me.
Hello,
I have experience with ultrasonic cleaners and keyswitches.
I have an Apple II Jplus with Datanetics DC-50 switches and some of them have contact problems.
I got rid of some of them using IPA but not all.
The problem is how they work internally, check this page for a schematic diagram of the contact plates:
https://deskthority.net/wiki/Datanetics_DC-50_series
Unfortunately there is a small plastic film that covers the contact plates that prevents a good cleaning by whatever substance You inject in the switch, so they are really difficult to clean without opening the case that is sealed.
I think an ultrasonic cleaner would be of little help and IPA should eventually be used (beaware that is flammable) instead of water because You would'nt be able to dry the internal plates otherwise.
There is a guy in an Youtube video that serviced datanetic switches by opening them (by fracture of the case) but it's risky business..
https://www.youtube.com/watch?v=YzzwPg8hkbo
As of today, I didn't figure out how to properly clean them without opening them.
Luca
I have a spare , broken, DC-51 switch and I tried to heavily apply contact cleaner spry to the switch. It looks like that applying contact cleaner (that contains petrol drivatives) as , probably, IPA , is not a good idea. The two gold leaves that are enclosed between a stainless steel plate and a mylar film do not get wetted by the contact cleaner unless You flood the switch and in this case the milar film will disconnect from the stainless steel plate since the glue in between gets dissolved.
As a result, I do not recommend injecting IPA in those switches.
Luca