Evaluating Your Chances

What are the chances of success in doing PCB-RE? It depends on several factors and your approach. Within each approach, the time and effort required will also increase with the complexity of the PCB, while the rate of success and the quality produced will be affected by the capability of the equipment or tool used, as well as the experience of the engineer doing the PCB-RE work. Quantifying the methods and their related factors into a single chart offers a rough but straightforward comparison as shown in the table below:

Another way of representation would be individual SWOT charts that give a sweeping view of each approach's strengths and weaknesses. The closer to the center (i.e. bullseye) a factor is, the better the weightage and vice versa.

No matter what you opt for, it is important that you have a good understanding of the process involved, not just the cost incurred. Other more specialized aspects of PCB-RE such as mobile forensics may require formal training to be proficient in performing the tasks yourself, unless you prefer to engage a professional to do the job. These exotic, CSI-like practices and many other PCB-RE methods are also covered in my best-selling book PCB-RE: Tools & Techniques.

Old but not Obsolete

Good things never die, even if they grow old. The same can be said about software, one in particular which I've fondly remembered since my early engineering days...

You might not believe me if I tell you that there's a community of PCB designers who're die-hard DOSbased OrCAD fans. For readers who've worked with the DOS version of OrCAD products, it may come as a pleasant surprise that these EDA tools, which used to cost from between $495-$1,995 individually or $3,995 for a complete suite, are now available for download complete with user and reference manuals. You'll need to register as a member first—subject to approval by the moderators of the group, though.

OrCAD ESP

OrCAD SDT

OrCAD VST

OrCAD PCB

The last DOS version is the OrCAD ESP 4.40 release which comprises the following modules:

• SDT 386+ 1.21 Schematic Design Tool
• VST 386+ 1.20 Verification & Simulation Tool
• PCB 386+ 2.22 PCB Layout Tool
• PLD 386+ 2.01 Programmable Logic Design Tool
• MOD 386+ 4.04 PLD Modeling Tool

I've worked extensively with the SDT 3.21 in my early engineering days from 1990-1995, mainly to draft schematics as well as flowcharts and 2D mechanical drawings for my test program set documents. To the hardware engineers in my company's engineering design department, this humble piece of software was just a toy compared to their powerhouse EDA suite from Mentor Graphics running on Sun's top-end graphical workstations. Perhaps, but then again there are many products out in the market which were designed and produced using OrCAD too.

So how do we run these legacy DOS software from within modern operating systems that are now the dominant landscape of most PCs today? The answer: Virtual PC or DOS emulator. And there are many flavors to choose from—Microsoft's Virtual PC, Oracle VM's VirtualBox, VMware Player, the open source DOSBox, etc. Most of these x86 machine emulators are free and they support and run different OSes such as Linux, Windows, OS/2, BeOS, and even the Mac OS X.220 I've installed and run Microsoft's Virtual PC and DOSBox with some of my favorite software of by-gone era just to re-live the good old nostalgic DOS days.

For more details and links to these resources, get a copy of The Art of PCB Reverse Engineering. The full-color and standard editions are similar in content, except the color edition costs slightly higher but hey, you get to see the illustrations and photos in their full glory!

X-Men Reverse Apocalypse

One of the best things about writing the sequel book PCB-RE:Tools & Techniques was having the opportunity to know and interact with nice and interesting people. John McMaster was one of them. I got to know him while searching for X-ray related PCB-RE information, and came upon his Twitter page on a home-brew X-ray machine which he designed and built for his IC reverse engineering work. In fact, his amazing tool was featured in a number of websites like Makezine and Dangerous Prototypes.

John was kind enough to give permission for me to include this project in my book, and he even provided me with the necessary X-ray prints of his endeavors, as well as his fun bio photo:

Of course, I was more interested in the PCB-RE aspect than the IC-RE which is his main focus. Nonetheless, being the helpful guy that he is, my requests were granted:

John went so far as to fill me in with the details of his home-brewed project through our email correspondences, which readers who bought the book would have the pleasure of learning firsthand from the 'master', Mcmaster himself. (pun intended)

So if you have not gotten a copy yet, you may want to get it here.

Manual PCB-RE: Instrumentation

Setting up an electronic lab like a commercial repair house is certainly out of the question,unless you're prepared to fork out a fortune to do so. But if you're thinking of doing PCB-RE manually, all you really need are just a couple of basic inexpensive equipment:

• Digital Multimeter (DMM)
• SMD LCR Meter
• Power Supply
• Universal Device Programmer
• Multi-Protocol Adapter

Most engineers should be well acquainted with the first three; the last two are not really for novice but can come in handy if you want to delve deeper and get a better understanding into the workings of a board.

Digital Multimeter (DMM)

The DMM is perhaps the most basic measuring instrument an engineer or technician will ever get to learn and use at work. Increasingly, digital multimeters are preferred over analog ones for their accuracy, functions and ease of operation, since they come with a numerical display that provides quick reading of the electrical entities being measured.

Choosing a DMM would seem like a no brainer but there are subtle yet important differences that separate a good model from an average one. Besides quality and reliability, resolution and accuracy are two primary factors that should not be overlooked. Though we're not particularly concerned with these traits when it comes to doing PCB-RE, it is imperative to get a DMM that has fast continuity test response.

This feature becomes apparent when you need to do a sweep on rows of connector pins to get a connectivity detection beep, so a slow response will potentially miss probe points that have valid connections. So invest in a good DMM to save yourself from this stigma.

SMD LCR Meter

Surface-mounted components are becoming popular with board designers due to the small sizes and space economy they afford. Some of these devices are so miniature there is hardly space for part numbers or even abbreviated values to be printed on them. Using the probes of a DMM to measure these devices can be challenging and frustrating. Enter the SMD LCR meter.

This remarkable and portable one-hand operated instrument identifies both marked and unmarked SMD-components with easy probing, passive or through-hole. A standard model can measure capacitance, inductance and resistance with speed and precision. Advance model can even check secondary parameters such as the capacitor's ESR, quality factor (Q),

dissipation factor (D) and impedance (Z).

SMD LCR meters come in different makes and functions. Those providing only basic functions may cost just between $20-$50 apiece, whereas more advanced models can run into $150-$300 an unit.

Power Supply

You have two choices when it comes to power supply: fixed and adjustable. Depending on what you intend to use with the power sources, you can opt for:

• Fixed power supplies with common voltages such as +5V, +12V, +3.3V, etc. which many PCBs require. A PC power supply unit will be adequate to provide these multiple outputs. But a note of caution: you will need to provide some kind of safety measures to ensure you don't fry the PCBs you're working on.

• Adjustable power supplies. These benchtop equipment are more costly but still affordable, and they provide built-in current limiting and over-voltage protections, plus you get to have a variable range of voltages at your disposal.