Mac Plus keyboard not working

There's a good chance that the problem is not in the keyboard or the cable, but in failing/failed capacitors on the logic board or analog board of your Plus. Replacing caps solved this problem for me. See lots of threads here about caps replacement, model by model.

Rick

There's a microprocessor chip inside the keyboard (the so called controller chip) which can go bad if someone connects a telephone headset cable.

There's also something on the Plus logic board which communicates with the keyboard, and that could go out for the same reason.

And of course, it's also possible that the machine needs new capacitors.

Have you tried a known good keyboard (if available)?

c

You didn't by any chance happen to use a telephone handset cord thinking it was the same did you? I've seen people do that. The pinouts are different. If you connect a telephone handset cord to the keyboard, you'll toast it.

Would love to try a new keyboard but can't find one. Even the local Mac dealer here in Wichita doesn't have them. Didn't use the phone cord because I read about what they can do. Checked the pinout of the cord and it's fine. I'll likely go the capacitor route.

To remove the screws, is there an alternate route rather than having to purchase a case tool from Apple? It's just a star bit, right?

Yeh, nothing fancy. A regular torx set will do. Size T15 if I recall.

Just don't use a short bit and a bit extender, because the bit extender will get stuck.

Just don't use a short bit and a bit extender, because the bit extender will get stuck.

Click to expand...

ballpoint pen tube works great as an extension.

and I did the phone cord thing a LONG time ago (late 80's) no harm done, keyboard and plus were fine.

If I remember right, there's a screw hiding in the battery compartment.

J White