A600 right Amiga key not working

[Amiga1992]

I'm really puzzled about this
My Amiga 600's right Amiga key stopped working. It's the only key not working on the system.

I tried re-seating the keyboard cable a million times in different ways and it never works. But if it was a cable problem, I would think a whole row of keys would stop working.

Any ideas what could be happening? This is an ACA620 system. It was working well before, can it have anything to do with the ACA?

It's really annoying, I can't reset the machine

[edit] removed the ACA620 and it still happens so it isn't that.
[edit 2] plot thickens, after a while it works again. And some times return key is erratic when right Amiga works. HALP!!! This machine has been recapped recently so don't go suggesting that, but maybe the membrane is giving up the ghost?

[Jope]

The membrane could potentially have a break in the conductive ink just next to the Amiga key.

.. or it's dust / shiny rubbers.

You can take the keyboard apart, wipe off any dust from the membrane with a damp cloth + dry it immediately with some paper towels.. Then look at the rubbers beneath the erratic keys, wipe them with some copier paper until they are no longer shiny, see that there is no dust left over (use some air duster) and reassemble.

Once you have it apart, you can see whether there are any dark spots in the conductive traces. Often if the laquer is broken, air starts getting in and the trace corrodes around where the break is.

[Amiga1992]

I will check for this, it's really weird that it works after a while, so maybe it's just dust. I hope the membrane is OK :/

Thanks as usual, Jope!