Bob Axtell wrote:
> Mauricio Jancic wrote:
>   
>> Hi,
>> 	I have two boards from a customer who wants me to produce identical
>> replacements. This are 10+ years old boards (Stepper controller) with a
>> bunch of logic, comparators, and some other parts. No microcontrollers.
>>
>> 	I would like to know if there is a set of tools available to
>> reproduce as exactly as posible a board, in order not to have to follow all
>> the traces with the multimeter and the make the schematic.
>>
>> Any ideas?
>>
>> Regards,
>>
>> Mauricio
>>
>>   
>>     
> Nope.
>
> --Bob
>   
OK, here is about all you can do:

Build or buy a very low ohmmeter; this is designed to deliver a voltage 
across the probes of no more that 100mV.
Routinely probe every OTHER point against one point. This will take a 
LONG time, possibly a week if it is more
than 2 layers. A normal beeper will NOT do, and MIGHT damage a 
component, too.

If you can remove all of the components without damaging the PCB, you 
can hook every pin up to a raw PCB tester
and "learn" the PCB. This little trick can be expensive, but MIGHT save 
time.

Once you have a reliable schematic, then verify the values of 
everything, and of course the digital devices. Be aware
that even when the exact PCB is created, it might not work because  HC 
devices have become MUCH more sensitive
to noise that they were 10 years ago.

Be sure to quote it high.

--Bob
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