Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!nic.MR.NET!umn-cs!berlin!grg
From: grg@berlin.acss.umn.edu (George Gonzalez)
Newsgroups: comp.sys.mac
Subject: Re: $300 Mac II ADB fuse repair
Summary: Apple's sad history with connectors...
Message-ID: <292@berlin.acss.umn.edu>
Date: 7 Feb 89 02:37:15 GMT
References: <11984@dartvax.Dartmouth.EDU] <76000341@p.cs.uiuc.edu] <12096@dartvax.Dartmouth.EDU>
Organization: U of M MicroGroup, Minneapolis
Lines: 32


> ( much discussion about Apple not using fuse sockets, ... )

If you look back, there's a very strong reason Apple shies away from sockets.
Apple has not done very well with electrical connectors.

On the Apple II, my most common problem was disk errors.  Cleaning the
card-edge connection fixed the problem every time.  Seems that Apple used
tin or solder plating on the card-edge connector.  The tin would corrode
and eventually fail to make good electrical contact.

  Also on the disk II controller, the connector to the disk drive was not keyed.
It could be inserted in many orientations, most of them blew out something
in the drive or controller.

  The II's chip sockets were also pretty flaky. Pushing down on the chips
was a well-known ritual whenever the II was acting up.

On the Apple III they had even greater problems with connectors.  I believe
they had to replace every board in the field due to connector problems.
(Was it the RAM chip sockets, or the inter-board connector? I don't remember).

I don't recall any connector problems on the Lisa.  They may have switched
to premium gold-plated connectors after the Apple III problems.

So Apple had quite a history of connector problems *before* the Mac.
Not too surprising that the original Mac had a minumum of electrical
connections:  No sockets for any chips, except ROM's.  Even so, they goofed
by using a very cheap, tin plated connector for the CRT yoke.  This
connector failed on a lot of Mac's, giving the well known "vertical line".

So its not too surprising that Apple engineers soldered in the fuse.