A4000 keyboard on A3000 - "0" key doesn't work? - IGNORE THIS POST

[dingebre]

Ignore this post. I'm an idiot.

I tested again and one keyboard it's now the #2 key that doesn't work and it's now the #2 and #3 on the other. Clearly something wrong with the keyboards. I also suspect they are really A3000 keyboards anyway, sigh...


Original post...

I have two A3000s and needed/wanted to replace the keyboards. I found a couple of what truly appear to be NOS A4000 keyboards with the same connector as the A3000 and A2000 keyboards I already had. When I plugged them in, the "0" key on the keypad doesn't work. All other keys seem to work fine. I disassembled one of the keyboards (it was pristine inside adding confidence these were NOS) and visually confirmed the traces on the membrane as well as verified with an Ohm meter. I also verified the resistance of the plunger was ok.

Is there some difference in the A4000 keyboards that makes the "0" key on the keypad not work? Did I somehow buy two keyboards with the same defect?

Both keyboards are "Amiga III technologies" Model KPR-E94YC, Amiga part number 365374-01

Thanks!
David

[dingebre]

The "Amiga III Technologies" keyboards are the ones manufactured by Escom that shipped with their A4000T, but they should be 100% compatible with the 2000, 3000, and (with a passive adapter) 4000 desktop.

Start by cleaning the pins on the connector plug in case they picked up some residue over years in storage. If that still doesn't work you'll have to move on to some more intense cleaning/repair.

Another diagnostic step: rapidly press the "broken" keys several dozen times or more. Do they eventually start working? I have an A3000 keyboard that sustained a wine spill decades ago and was never 100% cleaned (and I still haven't gotten around to fully disassembling it properly! ). Most keys don't work initially, but if they're pressed enough times they will eventually "wake up" - my assumption is that the physical action wears away enough of the residue on the membrane for the keys to make contact - until I don't use the machine for months on end and then need to repeat the process. All that to say that this might help you diagnose a dirty membrane compared to a more substantial electronic/chip/circuitry issue.

Thanks for not ignoring me 

The explanation regarding what the keyboards are is useful and interesting especially that they should work with the A3000. I'll give your suggestions a try. I have some cannibalized parts from a donor keyboard if I need something.

David