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Apple /// Keyboard Issues

Posted by: RegenKonig on 2026-09-05 20:19:54 Hello everyone! Unbelievably so, I am a proud new owner of an Apple /// 12v model. The machine works right out of the gate, it's tested pleasantly well so far. Floppy disk drive doesn't read, but I'm certain that just needs a deep cleaning, and lubrication job. My bigger issue at hand... the keyboard. Some keys don't work at all, as for the ones that do? They repeat themselves many times, even when the key is lightly pressed ever so quickly. I have already taken fresh solder to all the through-hole pins on the keyboard, reflowing all of the joints. I have also applied a little bit of DeoxIT to each of the keys, working the mechanism thoroughly as I went along. I'd love any and all input regarding this machine. It's been a dream catch of mine for a very long time, paired with the ProFile, and the fact it's an earlier revision... I'd love to get it to sing and dance, and show it off for the world to see more of.

Posted by: bibilit on 2026-09-05 22:08:00 As some keys are missing altogether, i am wondering if something has been dropped on top of it. Look for any damage in the pcb or any key which is not level with the others.

Posted by: D_O_S on 2026-09-05 23:23:24 Previous owner of this machine here! Unfortunate to hear of the keyboard issues. In terms of rough handling...the owner before me was a very meticulous collector of 35yrs, and had It nicely packed away since 2000-2002 ish, and claimed his ///s worked in a "usable" as late as 2008. Still a possibility though, storage isn't kind to these things. I would maybe check the 341-0035 chip (or 342-0136, although that's usually on 5V boards). This is the keyboard encoder chip, and is responsible for actually dealing with the data sent from the keyboard. It could be failing and shorting one of the lines to ground. Check the data sheet for the pinouts and test that if you want to be more meticulous. If not, donate the 342-0035/342-0136 from the donor board I gave you, and socket it into the place of the current one, then test. I think JCM also makes a replacement keyboard encoder if they're both bad. Called the "JCM Universal Keyboard Encoder" iirc. That chip may also explain the multiple characters per press. A more annoying measure to take would be to desolder one of the "working" key switches, and take it apart to clean thoroughly with DeOxit. I had to do that recently with my Amiga 1000's keyboard, as they're sealed and hard to clean externally. The ALPS SKCC switches are not sealed like the Amiga's, but it does mean debris and such can work their way into the switch, and would been to by physically removed, or the switch taken apart for it to escape. In short, clean/replace 341-0035/342-0136 keyboard encoder chip on J13(?), and possibly take apart one of the switches.

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