From: "Michael A. Terrell"
Subject: Re: Open Source Consumer Products
Date: Mon, 25 Nov 2002 10:12:20 -0500
Organization: Have you seen my bench? No, really! Where is it?
X-Mailer: Mozilla 4.61 [en]C-CCK-MCD (Win95; U)
John Woodgate wrote:
> I read in sci.electronics.design that Michael A. Terrell
> wrote (in <3DE14DFD.email@example.com>) about 'Open
> Source Consumer Products', on Sun, 24 Nov 2002:
> > A decent service manual can be cut and pasted from test procedures
> >used at the factory, as well as the full bill of materials can be cut
> >and pasted from the individual BOMs for each board / module / assembly.
> >Everything needed to create a manual already exists, and should only
> >take a couple hours work from a secretary to put the material together.
> A widely-held view, but compiling a service manual, **that a technician
> coming fresh to the product** can use without confusion, is actually a
> specialist job.
> For component-level diagnosis, a functional circuit description is
> necessary, together with tables of the effects of faults in selected
> components. These faults may be simply open or short circuits down to
> drifts out of tolerance.
> Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
> Interested in professional sound reinforcement and distribution? Then go to
> PLEASE do NOT copy news posts to me by E-MAIL!
John, the test procedures I have used (and written) had a functional
circuit description, if needed, and every product had a block diagram of
the entire product, so most manuals were produced by cut and paste. The
entire set of test procedures, and even test fixtures were available if
a customer wanted to buy them. The last product I worked on had a five
inch thick stack of test procedures from the board level, module level,
and complete system. If a company is using test procedures so poorly
written that they can't be the basis of a service manual, they are
forcing their techs to work with a handicap and costing themselves
Michael A. Terrell