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September 2004

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Subject:
From:
Roger Gathright <[log in to unmask]>
Reply To:
Roger Gathright <[log in to unmask]>
Date:
Tue, 21 Sep 2004 09:54:00 -0700
Content-Type:
text/plain
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text/plain (91 lines)
Before you pursue a reverse engineering task, be sure that all the
components, or reasonable replacements are readily available.   I
went through a similar exercise a few years back, and got the whole
board laid out and when we tried to assemble the pre-production
samples, hit a wall. The parts "ARE" available, for repairs, but
orders of several thousand were not possible, out of production.
Just a heads up!


----- Original Message -----
From: "JaMi Smith" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, September 20, 2004 6:24 PM
Subject: Re: [DC] A Reverse engineering question


> Scott,
>
> You called them? did you ask them if you could buy a copy of the
design files
> (gerbers etc,) and make a copy for their former customer? They
might look at a
> little differently under those circumstances.
>
> If you are convinced that all other avenues have been exhausted,
and you feel safe
> in trying to reverse engineer it yourself, there a few basic
questions.
>
> Is it SMT or Thru Hole?
> Components on one or both sides?
> How many of the layers are planes?
>
> If you are lucky, it will be something simple like 2 routing
layers, two planes, and
> then 2 more routing layers, wherein you can actually see all of the
traces under the
> right "lighting" conditions once components are out of the way.
>
> An important question here is whether there is a Sacrificial Sample
available. By
> that I mean is there a board available which you can remove parts
from, where the
> parts can be sacrificed for the cause, and the board will not be
required to be used
> again?
>
> If so, then it should be pretty easy to remove the larger
components so as to be
> able to see under them and hence make tracing things easier,
including being able to
> see thru the top routing layer to see the routing one trace below.
The trick here is
> to sacrifice the parts (by cutting the leads, etc.) so as to not
damage the PCB.
>
> Are all components clearly identified, or are there some parts with
"in house"
> numbers on them (or no numbers at all) that you will be expected to
identify in the
> course of your "reverse engineering"?
>
> Just how much "reverse engineering" will you be responsible for
(are you expected to
> reproduce a functional replica, or just provide their engineering
department a
> schematic that they will review and accept final responsibility
for)?
>
> Other very important considerations would be just what kind of
functions the board
> is used for, in that if it has any sensitive low level analog
circuits of some high
> speed digital sections or places where controlled impedance
transmission lines are
> used (LVDS, ECL, or RF), there may be far more than just a point to
point connection
> of traces involved in functionally replicating the design.
>
> Food for thought . . .
> JaMi

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