Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!rochester!uhura.cc.rochester.edu!ur-valhalla!davis
From: davis@galaxy.ee.rochester.edu (Al Davis)
Newsgroups: comp.sys.zenith.z100
Subject: Re: dead control key
Message-ID: <2097@valhalla.ee.rochester.edu>
Date: 11 Apr 89 04:56:34 GMT
References: <8904091716.AA31502@sdimax2.mitre.org>
Sender: usenet@valhalla.ee.rochester.edu
Reply-To: davis@ee.rochester.edu (Al Davis)
Organization: UR Dept. of Electrical Engg, Rochester NY 14627
Lines: 22


key repair procedure:

unsolder the bad key (use braid)

pull out from front (requires good dexterity) squeeze clips & rock until it
comes out.

take apart (clips on side hold it together)  don't lose the tiny coil spring.

There is a metal flap that sort of forks.  Bend it out so pusher puts more
pressure on it.  (failure mode: fatigue of this metal flap)

reassemble.  test with ohmmeter before re-soldering.


other possible problems: flux eats through the foil on pc board


the keys are designed for a certain service life, some number of
operations.  This means you can expect a lot more of this kind of failures,
soon.