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Repairing a faulty AppleDesign ADB Keyboard

After setting up my G3 266mhz, I found that I couldn't play Transport Tycoon. The game worked perfectly, apart from very soft music volume, but I couldn't work out how to actually move around the map. In DOS or Windows TT, this was a right-click-and-drag, which was obviously not a thing on a single-buttoned Mac mouse. I tried opt/cmd-click to no avail.

I then realised that the UP cursor key worked, but no other directions. Back in Finder... only UP also worked. Trying a little harder, I then found that the outer-ring of keys on my AppleDesign ADB Keyboard failed to respond at all!

I mean... you only have to look at it externally to see that it's had a hard life! Stickers... yellowed-plastic.. time for an autopsy.

Opening it up...

There's 6-or-so screws underneath, and a few clips along the bottom which'll need to be prized open. There's then 6000 screws holding the black metal plate to the back of the internal keyboard frame. Enjoy.

The first obvious-ness was blistering contacts. This damage happened to be exactly on the cursor keys which didn't work... but a continuity test showed that this wasn't actually a problem.

The next obvious-ness was a serious amount of water damage on both sides of the membrane.

The real damage was black/broken traces. These are painted onto the plastic, so there's no soldering here, unlike when I fixed the eMate 300.

Yeah, you'll just have to pretend the silver parts above are black. They were black. Unfortunately I didn't take a photo prior to fixing the bloody things! Actually, you can just see an example of the-blackening on the traces over on the far-right.

Fixing it

As you can see, I failed to take a 'before' photo, but whatevs. I first tried to use my Circuit Pen, but it turns out it had dried up all by itself. I had done everything right, the lid had been securely on during storage, but the pen was somehow rendered useless. Just for fun, I cracked it open and tried to use the contents, but they were taking WAY too long to dry on the plastic.

Instead, I went back to Jaycar and bought a vile of silver conductive varnish. On the rack in the shop, this product looks like clear resin.

The silver-ness of it actually settles to the bottom of the vile and I had a hard time finding it.

A quick shake fixes that tho! Once shook, I used a toothpick to bridge all busted traces...

Unlike the circuit pen, you can lather this shit on. It takes no time to dry and the resistance dropped to ~0ohms very quickly!

In no time, many games were played.