Keyboard fun!

My keyboard is missing a key. There’s no escape!

Well actually it wasn’t escape that was broken on my nice click-a-dee-clack Amiga 4000 keyboard, but CAPS LOCK! And bit even the key itself, it was the LED that just wouldn’t show the status. No problem, let’s take it apart

So many screws!

At first I thought the LED might have died after my recent diode intermezzo on the Amiga board. But measuring with my multimeter I see that the LED is just not getting any power. Let’s look at the membrane.

It seems I forgot the before picture

There was a piece of the trace missing. It seems it had corroded away. The previous owner probably spilled Coke on it. My first approach was to scratch the green cover of the existing trace so I can connect to it.

Then I covered it with some of my copper foil. I wasn’t expecting it to work, really, but it was worth a try because I didn’t have a conductive pen, and certainly soldering is not an option, unless you want to buy a new membrane (these are the same as the A500 membranes and are available). But my better half is trying to make me frugal, and we the people are creating too much e-waste anyways. So I ordered a nickel conductive pen on Amazon. It arrived today.

I connected the two distinct pieces of the trace to each other with the pen, and after the ink dried, covered it with a piece of copper foil again, for no other reason than that it is shiny. Aaaaand……:

Off and …
Houston, we have continuity

Putting the while thing together again.

Shiny, and good as new!

While testing, I’m actually not using the keyboard on the Amiga, but in my PC with a little adapter that I built with a cheap Arduino Pro Micro clone and tkoecker’s amigakb.

Awesome keyboards for all computers!

I ordered the boards through PCBWay and they’re super easy to solder. I have 9 more, because I didn’t want to pay more for shipping than the PCBs. So if you want one, drop me a note.

Recap of a revised recap

When I got my A4000 late last year, I could not have been a happier kid. I fleas surprised to get it for a fabulous price and it arrived just in time before the holidays.

The A3640 was a good first victim. Notice the through hole caps that ripped off the pads

That joy lasted until I noticed that there was no mouse, a Super Buster r6 (WTH) and a semiprofessionally done replacement of all the capacitors on the board. Unfortunately through hole caps were used in the recap process.

You will find enough discussion about this on the internet, and people will suggest all sorts of craziness, like twisting off old caps or putting through hole caps on SMD pads. These are all terrible ideas. Don’t do it. If you have an Amiga (or any 30yr old computer), do it right or pay somebody to do it right. Recap services are not expensive and are definitely worth it.

One of the tricky parts is that the silk screen on the A3640 is incorrectly showing the direction of three capacitors. Make sure to consult the schematics.

Ruined! It is ruined! Or is it?

When I reached out to the southern California Amiga repair wizard Acill (Paul Rezendes), he suggested that I check out this video on repairing pads. I had to watch the whole thing twice, because it’s mind blowing. But hey, nothing that can’t be done, so here we go

This one is even worse. The pads are gone and the vias look corroded.
Got some copper foil in the mail, 1.4mil

It took me a while to get these right. I bought a cheap scalpel on Amazon
A cheap microscope is worth gold

To glue the pads on I used 2 component epoxy overcoat and let it dry over night.

It’s really tricky to keep this orderly awhile trying to connect the vias to the pads.

I spent a lot of time with my multimeter and the A3640 schematics, measuring the continuity of the pads

But the end result is pretty solid.
And we are online.

This one is certainly not winning a beauty contest. But for a first attempt in fixing a botched recap, I am proud to say that the card is now better than before I touched it.

Time to build a 68040 to 68060 adapter next!?