retrotechtivePowered up the A4000 finally... and discovered that CTRL AMIGA AMIGA was no longer working.
Amiga Test Kit clearly shows this entire set of keys are unresponsive.
And here's why. Can you see it?
This is typical for these membranes over time, both my A500 and A1200 had similar issues. The thin, paint-like traces simple get corroded and stop conducting.
No continuity between the connected Amiga key and the next key along the line to the right.
Here's the same area after I lightly scraped the trace. The whole area just flaked off. (NB: don't try this at home... well, unless like me you know you need to replace the membrane 😂 )
Doesn't look "lightly" scraped on that photo, those scratches around it look like I went at it with a chisel. But those scratches were already there, which is interesting. Someone else been in here maybe?
Given the dirt I found inside, it actually seems unlikely! Ugh.
Also makes me realize if I'd opened this up when I got it, I might possibly have stopped the rot by cleaning this crud out. Maybe not though, they tend to fail over time anyway.
Fortunately, these membranes are the ones used in the A500 - so should be easy to replace. I might in fact temporarily "borrow" one from my spare A500 keyboard until I get a new one. Possibly, a posh PCB based one if I can! (The A1200 has one of those, and it's soooo much better!)
Craig Harrison@retrotechtive My A600 needed a new membrane. Quick and east fix. When my Sam Coupe needed one, that was less easy to locate a replacement, so it now has a full mechanical keyboard with non clicky / tactile switches, thanks to #Quazar. Such a nice machine to type on.
@craigsbar I can imagine a Sam Coupe being a challenge to repair! Quazar is a one person army for that machine, lots of passion :) Wish I had a Coupe myself though!
@retrotechtive I bought mine a few years ago now. On ebay listed as broken.... with a couple of photos at the start of the listing showing it filthy and then a couple more photos showing it booted to a basic prompt. It was listed as BIN for 250GBP with 25GBP for postage to Ireland. I thought well if it boot to basic then the ASIC/ULA is OK and everything else is replace or repairable so I bought it.... what was wrong with it in the end. The Floppy Drive belt. after a good clean it looks good.
@craigsbar Nice! Looks in good shape too!
@retrotechtive It is. It took some tlc when I got it. Drive belt and a really deep clean. the white case was brown with dirt.