Sometimes, we have an electronic device in our care that needs repairs. As we all know, these electronic devices are fragile and are very susceptible to faults. This is why a clear, detailed circuit diagram is available to troubleshoot the device. What if this device has no such information? Perhaps, the PCB is already out of circulation?
Do you think this makes repair impossible? Well, even though some things are fundamentally impossible with engineering, this isn’t one of those things. Basically, the only way out is to recreate the PCB electronic circuit, i.e. reverse engineer the circuit board.
But how is this possible? And how is it done? Sit back, relax, and learn.
What is PCB Reverse Engineering?
PCB reverse engineering is a process by which we replicate the functions and specifications of a particular printed circuit board. We usually do this by analyzing and dissecting the electronic circuit based on the information provided in a manufacturing document.
This is regarded as one of the most tedious tasks in engineering as it entails moving from a point where you have almost no experience/information about what you are to do, to a point where you have everything you need to actually produce the printed circuit board.
Why Do We Reverse Engineer Circuit Boards?
If it is so difficult and tedious, why do we even bother doing it? That’s a good question. We carry out reverse engineering of PCBs for a number of important reasons;
- To replace obsolete components on the board
- To reposition certain components
- To enhance the functionality of the PCB
- To analyze and reinforce the security requirements
What Do You Need to Reverse Engineer a PCB?
Get your tools ready, it’s going to be a long ride. The tools you will require depend on the complexity of the project. If it is a simple PCB, you can just disassemble and analyze the circuit using a pencil and paper, using the standard symbols for easy understanding.
If the circuit is more advanced, you will need hardware and software tools. Tools like AutoTrace, pstoedit, Dia, Gimp, and Inkscape are all useful.
Process of reverse engineering of a circuit board
Steps to Reverse Engineering a PCB
Prepare the Pictures
Take a well-lit picture of both sides of the PCB. If you’re taking a picture, ensure that the resolution is high enough. Some experts recommend using a scanner but this is often inconvenient because of the varying heights of the different components.
Import the Pictures and Ready Them for Editing
The next step is to load the picture on your favorite editing tool. Use the import or open button and when you can edit the picture, crop the edges of the PCB so you only have the board to work with and then make sure the board is properly placed via the rotation options. Also, make sure you use the zoom/magnifier tool to ensure that the pertinent sides of the PCB are well displayed. You can also consider reducing the opacity of the picture to around 50% to 75% to ensure that it is as transparent as it needs to be.
Blend the Images
You can either use the Screen Blend option or the Luminosity Blend to complete this step. These are both available on the Adobe Fireworks app. With the Screen Blend, dim the copper layer by setting the contrast filter to -50. Highlight the copper trace and then choose the blend mode. With the Luminosity Blend, it is almost the same, the only different thing is that you use the Levels filter, rather than the Contrast.
Brushing the Picture
With the copper trace already highlighted, you can see a network of lines connecting the solder pads and the holes by using the brush tool. When doing this, make sure your brush has a color that is different from that of the solder mask.
Next, extract the solid color with the use of the Levels or the Threshold filter and then adjust the saturation filter to select a preferred color to track the hue. Now, set the opacity to around 70 and you will see the intensity.
Record the Values you Get and Replicate on a CAD Software
Run the circuit on software and see the results.
Reverse engineering a PCB is a difficult task that might prove impossible for a beginner. Why don’t you allow our team of seasoned experts to help you with this task? You can reach out to us today and we will walk you through your needs.