create schematic from circuit board images?

[All Bumbed Up]

This is a long shot, but is there any software out there that will take
a circuit board with components and create at least a rough schematic
from it? I realize that board and components would probably have to be
overlayed. Just curious.

[Jeff Liebermann]

Automation would be nice, but I do it by hand, with the aid of a
computah to do the photo manipulation, drawings, and to connect the
dots. Something like this:
<https://www.instructables.com/id/How-to-reverse-engineer-a-schematic-from-a-circuit/>
The difficult parts (for me) are identifying the components and
photographing the PCB inside the original box, where the tangle of
wires and mechanical parts usually get in the way. I've never tried
to reverse engineer something as complex as the above example PCB.
Even with simple PCB's, I always wiring errors and component errors.

Plenty of articles and videos on other ways to do it:
<https://www.google.com/search?q=circuit+board+reverse+engineering>
I should probably read/view a few of these to see what I've been doing
wrong:
<https://www.google.com/search?q=circuit+board+reverse+engineering&tbm=vid>
<https://www.youtube.com/results?search_query=circuit+board+reverse+engineering>

Incidentally, if you have more than one of the PCB that you're trying
to reverse engineer, I've found it better sacrifice one PCB to the
electronics gods by removing all the parts and photographically
reproducing the PCB. Once the holes are located and cleared with a
solder sucker, it's easy to photo graphically locate the holes (light
from behind the PCB). Then, using a continuity checker (buzzer or
light), just connect the dots (holes) and you have a schematic. The
hard part is to NOT rip out the plated through holes when removing the
components. Chop off the component, leaving the leads. Heat the
leads with an SMD hot air desoldering station, and pull out what's
left of the lead with a pliers or tweezers. Then, clear the holes by
heating the PCB, and either blowing solder slag all over your
workbench, to sucking the solder out of the hole with a desoldering
pump. Solder braid will tear up the pads and traces and should be
avoided.

Good luck.


--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[Ron D.]

Target 3001 https://server.ibfriedrich.com/wiki/ibfwikien/index.php/Reverse_Engineering has a facility that can help.

You start with an image of the board, Then add components to another layer and connect the components. The schematic then comes out as "rats nest" that you have to sort out.

[John Robertson]

On 2020/02/25 12:03 p.m., Ron D. wrote:
> Target 3001 https://server.ibfriedrich.com/wiki/ibfwikien/index.php/Reverse_Engineering has a facility that can help.
>
> You start with an image of the board, Then add components to another layer and connect the components. The schematic then comes out as "rats nest" that you have to sort out.
>
>

It would appear that KiCAD is also a possibility for RE:

https://lists.launchpad.net/kicad-developers/msg07628.html

(I have Target 3001 as well)

John :-#)#

[All Bumbed Up]

On 2/25/20 3:03 PM, Ron D. wrote:
> Target 3001 https://server.ibfriedrich.com/wiki/ibfwikien/index.php/Reverse_Engineering has a facility that can help.
>
> You start with an image of the board, Then add components to another layer and connect the components. The schematic then comes out as "rats nest" that you have to sort out.
>
>

Thanks, downloaded and tried it out today, but ran into a couple of
hitches. I was trying to use the instructions shown at the above link:

1) I refer to step 4, import packages. It says to place it on the
layout, which I did, but does not indicate how to release it there so it
stays put. How is this done? Tried double clicking, etc but to no avail.

2) I was trying to place a 555 timer. It was only about half the size
of the image underneath. Which can I reduce/ enlarge and how?

That's it for now. If remedied, I can then try proceeding forward to
the next steps. I am using a simple, single sided board with less than
30 components, which are mostly resistors, capacitors and diodes.

Thanks in advance!

[All Bumbed Up]

On 2/26/20 5:48 PM, All Bumbed Up wrote:
> On 2/25/20 3:03 PM, Ron D. wrote:
>> Target 3001
>> https://server.ibfriedrich.com/wiki/ibfwikien/index.php/Reverse_Engineering
>> has a facility that can help.
>>
>> You start with an image of the board, Then add components to another
>> layer and connect the components.   The schematic then comes out as
>> "rats nest" that you have to sort out.
>>
>>
>
> Thanks, downloaded and tried it out today, but ran into a couple of
> hitches.  I was trying to use the instructions shown at the above link:
>
> 1) I refer to step 4, import packages.  It says to place it on the
> layout, which I did, but does not indicate how to release it there so it
> stays put.  How is this done?  Tried double clicking, etc but to no avail.

Alright, have to press the ESC key. Got it.

>
> 2) I was trying to place a 555 timer.  It was only about half the size
> of the image underneath.  Which can I reduce/ enlarge and how?

Still not sure about this one.

>
> That's it for now.  If remedied, I can then try proceeding forward to
> the next steps.  I am using a simple, single sided board with less than
> 30 components, which are mostly resistors, capacitors and diodes.
>
> Thanks in advance!
>
>

One other thing I'm running across. Not all components on the circuit
board can be readily identified. There is a flyback, for example, that
doesn't show up anywhere in data as well as what looks like a small
torodial transformer would with input and output turns. How can I go
about adding these unknowns?

[All Bumbed Up]

This evening, I identified values for almost all of the components in
preparation for placement tomorrow.

I solved the issue of scaling differences between the board and the
components. I just had to reverse the length and width specs.

There are still two components I have been unable to locate, what I
believe is a line filter (a bifilar toroid with bifilar input and
output) and a 9 pin flyback. Nothing comes up in cross reference online
nor on the database Target 3001 offers, so would welcome any suggestions
as to what to do here.

Otherwise, I think I'm ready to proceed.

[Jeff Urban]

>Not all components on the circuit
>board can be readily identified

That can be a problem. You probably have to do it manually but then figure out how to work it into the drawing in the software.

Another thing is two sided boards have been around for a longtime, I have no idea how you put that together but you can bet you have to depopulate the board to get a picture of it.

It might be a good idea to try it on a board that you know, well the schematic of. You can get used to what kind of errors and other shit you can run into.

If you got more than a two sided board, like four layers which are in many things now, such a program will not do much good. The outer foil patterns could be nothing but a power plane and a ground plane. The real works is hidden underneath.