Maintenance PCB
Maintenance PCB
(OP)
Hello,
I´m looking for equipments/devices for fast and accuracity fix PCB that we don´t have drawns/schematics or information about what it is used for.
Please, some of you has a laboratory with this kind of equipment that could share?
I search some equipments that uses Impedance curves to create basic condition information when the PCB is good and compare with other with malfunction.
Let me know if you know how this kind of equipment works and if has other kind of technology.
Thank you so much,
I´m looking for equipments/devices for fast and accuracity fix PCB that we don´t have drawns/schematics or information about what it is used for.
Please, some of you has a laboratory with this kind of equipment that could share?
I search some equipments that uses Impedance curves to create basic condition information when the PCB is good and compare with other with malfunction.
Let me know if you know how this kind of equipment works and if has other kind of technology.
Thank you so much,





RE: Maintenance PCB
TTFN
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RE: Maintenance PCB
I think he's asking about some sort of reverse engineering equipment which attempts to determine the circuit of a PCB based on test results between PCB nodes. I've heard of this technology but have never had cause to use it or explore it - a PCB house which did some work for us a few years ago had something along these lines.
RE: Maintenance PCB
There are multiple brand names. I can't recall the model we have at work.
EDIT: Huntron 2000
Just Google 'curve tracer' and many will pop up.
RE: Maintenance PCB
This is what I´m looking for....
Thank you so much.
RE: Maintenance PCB
RE: Maintenance PCB
Bear in mind that the cited type of instrument will only be even marginally useful if all you have are transistors and diodes on the board. They're basically useless for digital circuits where the faults are internal or non stuck-at faults.
TTFN
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RE: Maintenance PCB
Experiences may vary with differing ratio of random internal component failure versus externally induced damage to an IO pin.
The Huntron used to be a popular instrument. The rise of ATE has largely supplanted manual troubleshooting for R&O, but requires detailed info on the circuit and investment.
RE: Maintenance PCB
To amplify VE1BLL's comment, while there is indeed a fraction of failures that can be attributed to the I/Os, the relative percentage of I/O failures relative to internal failures has grossly increased over time. In 1977, a 10" x 10" PCB might have had about 100 TTL SSI and MSI components, typically with 14 or 16 pins and maybe 10 internal components per pin. Today, a single FPGA with 400 I/Os might have 10 million internal components, which is a ratio of 25,000 internal components per I/O pin. I/O pins are much more susceptible to failure than internal components, but even allowing a factor of 100 higher failure rate, that would still put the internal component to I/O pin ratio at 250:1.
Another general comment; a curve tracer is also quite blunt as a diagnostic tool, particularly since it's really only useful for testing the diode characteristic of an output's drain or source junction, or an input's ESD protection diodes. If a junction is shorted, or an input gate is blown, then the I-V curve will look wonky. But, if the input metal trace is vaporized, there will be no obvious I-V curve error.
TTFN
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RE: Maintenance PCB
The 'factor of 100' might not be accurate. Perhaps the ratio varies between mil-spec vs industrial grade parts. Random internal failures from latent defects are exceedingly rare in mil-screened parts.
I agree that the utility of such curve tracers has diminished over the years, but many industries are still dealing in supporting older tech every day.
It's simply a tool in the tool box.
These days ATE is so quick and easy that it's the way to go. But you need to know what the card or box is supposed to do.
RE: Maintenance PCB
To use ATE equipments for house laboratory appear to be expensive. Do you know a user hand manufactory for ATE or recommend a way for this kind of task?
At least I saw from Digital Test company appear expensive.
RE: Maintenance PCB
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Maintenance PCB
Adding a connection adapter and code for the next UUT becomes relatively cheap.