PCB Reverse-Engineering

[Fraser]

Excellent 

Thank you 

Fraser

[cdev]

Are there techniques in your book which can be approached without expensive equipment? (besides a good analog scope and multimeter)  Or home-made instruments.

[Singapura]

@cdev

Nice to hear from you!

When writing my book, I had in mind the most basic tools that any electronics engineer or repair technician has in his or her possession. My emphasis is twofold:

1. Strategy (steps) for different types of board
2. Visio-related instructions and examples on creating PCB layouts and schematics, including advanced topics like layering, smartshapes, and deciphering PAL devices.

Basically, the book content is organized into the following six chapters:

1. Pre-requisites - What you need to know as a minimum requirement.
2. Preparation work - Things (data) to get ready beforehand.
3. PCB layout - Technique for drawing the mechanical and layout of a PCB.
4. Schematic entry - Reconstructing the electrical diagram of a PCB.
5. Advanced topics - Additional techniques.
6. What next? - Some suggestions and pointers to further your learning.

You can go over to my website (www.visio-for-engineers.com) in the Blog section to view the posts for some idea.

Ps: Is that a Brocoliflower (a cross between broccoli and cauliflower) for your avatar photo? 

[Fraser]

I was wondering the same about the Avatar. I have eaten one of those but have no idea what it is 

I can also confirm that the book is perfect for hobbyists as well as professionals. I have built up a collection of reverse engineering equipment but the book provides the all important techniques to approach, what can be, a daunting task. I already have Visio but it is not essential and readers should not be put off this book because of the Visio content. Readers can adapt what they learn to their own needs. 

In many cases, reverse engineering is more about the logical approach rather than how many clever pieces of equipment you have. I believe it would be fair to say that the essential tools for the task are datasheets for all IC's, A good magnifying glass/microscope and a decent multimeter with fast responding continuity. Avoid multimeters with slow continuity response as they are VERY frustrating to use and slow you down. I use a Fluke 87III and, though relatively expensive, I recommend it as a quality product with great continuity response. You can brush the probe over some IC pins and immediately hear any 'hits' when continuity tracing. 

I have dipped in and out of this excellent book and can heartily recommend it to all. Money very well spent on a well written and produced book. Mine came from Amazon and is actually printed by them. I showed the book to my father, who has a background in Aero engineering (Rolls Royce) and he was very impressed with it, both in terms of writing style and overall quality. For me that was quite an endorsement as he is, like me, is a perfectionist 

I also recommend Visio to anyone who needs to draw technical diagrams. My copy came from Microsoft as part of their employer partner program, so only cost £10. It is worth checking if your employer or college have a similar partner agreement with Microsoft as it will save you a lot of money.

Aurora

[Singapura]

Hi Aurora

Thanks for the kind comments and review of my book. Would appreciate if you could put it up in the Amazon review, if possible. 

There's nothing more satisfying than to know that my readers enjoy the content of the book as much as I enjoyed writing it. There were days when I went to bed after completing halfway through a topic, but not wanting to make my wife worry for the late nights I put in, just to give her some assurance and good sleep, but ideas and words would still be flowing through my mind while I drifted into dreamland.

Hearing such good review from an experienced engineer like you, with a double endorsement from your dad who's also in engineering (aero-engineering... I mean, wow! I've had a short stint of three years part time in the aerospace subsidiary of my parent company and I admire the kind of knowledge and skill sets these engineers were involved in) just makes me feel that the one-year of sweat and hard work has been worth it all! I can't wait to share your review with my wife who had been very supportive and understanding; I'm sure she'll be very delighted too!

You sum it up well what PCB reverse-engineering is all about. In any engineering discipline, an equipment however sophisticated and powerful, is just a tool to help the engineer get the job done. How it can be effectively used to its full potential will depend on the engineer's mastery of its operation and functions, as well as the engineer's grasp and approach to the task on hand. The tool is only as good as the craftsman.

I'm sure other aspiring engineers following this thread will readily appreciate your recommendations of the essential tools required for taking up the challenge to do PCB reverse engineering. I hope they'll also see the power and versatility of Microsoft Visio and consider giving it a go. (There's a 60-day trial copy downloadable from Microsoft website.)

Singapura

Ps: My wife cooked that brocoliflower once for dinner; I thought it tasted kinda raw and told her I still like them original than in the hybrid form. (grin!)

Pps: I'm also in the process of collating a comprehensive SMD code e-reference (500+ pages) which I'll make available (hopefully before end April) for free to buyers of my book, along with the freebies that are already available for download on my website. So keep a look out in my blog!

[Fraser]

I have just left a short, high level, review of the book on Amazon.co.uk. It is going through the approval process so should appear soon. It basically says....buy it !    I am certainly glad that I did so.

Aurora

[all_repair]

I have just left a short, high level, review of the book on Amazon.co.uk. It is going through the approval process so should appear soon. It basically says....buy it !    I am certainly glad that I did so.

I was waiting for your verdict last few days.  Just placed my order, Singapura probably live a few streets round my block, yet I have to get the thumb up from UK and get the book shipped from the US.

[Singapura]

Hi Aurora

Thank you so much for your strong endorsement and support!

I was delighted to see the five star review you posted on Amazon.co.uk and shared it with my wife who's current on official business in Thailand. She was so elated! 

I'm not sure if your review will be reflected in Amazon.com (US). If it's not too much trouble, hope you can do me an additional favor by posting it there too. To date most of the orders are from the US but I have yet to see a review from my readers there. Besides UK, there's also an order from Amazon.de which is pretty encouraging to me.

@all_repair, you live in Singapore too? Didn't expect a fellow citizen to be this active on EEVblog. What a nice surprise!

PCB reverse engineering is quite a niche discipline in the electronics arena, so I don't really expect my book to become a best seller like novels that appeal to global readership, just the community of electronic engineers who're interested in this subject. But so far after nearly two months the book has garnered a relatively good response, in fact above my expectation. In the process I made some nice friends, people of similar profession and passion from across the oceans. It's a wonderful and rewarding journey being a first-time author! 

Singapura

[Singapura]

Just to announce that I have put up another bonus ebook for downloading free to all who purchase my book.
Here's the link:

http://www.visio-for-engineers.com/blog/another-bonus-ebook

It's an SMD Codes Reference Book containing over 500 pages and nearly 24000 code references to help in identifying small SMD devices with markings, for repair as well as reverse engineering purposes.

Thanks again to all my supporters out there. Cheers! 

[Fraser]

Thank you 

Aurora

[dds737]

Here was mentioned Wavetek SF10 tool, here is link on ebay for this relatively difficult to find tool:

http://www.ebay.de/itm/121630331225

Regards,

dds737

[Fraser]

@dds737,

Great find   

These are getting very hard to find so you have to take advantage of such opportunities when they appear.

Thank you 

Aurora

[dds737]

You're welcome. Looking forward to buy your book next month :-)

Regards,

dds737

ed

[Fraser]

For those unaware of the Wavetek/Meterman/Fluke SF10, here is a post I made some time ago, complete with internal pictures.

https://www.eevblog.com/forum/testgear/wavetek-sf10-short-finder-a-very-useful-tool-if-you-can-find-it/msg258070/#msg258070

Aurora

[Fraser]

I have just finished reading this book from cover to cover.

I am pleased to report that it is a most excellent read that is written in a style that is friendly and engaging. It covers its topics very well and with excellent pictorial support.

I have been reverse engineering PCB’s for all of my 40 years working with electronics, 27 of those years were in the professional world. I would be the first to admit that I am self-taught, and have improved my techniques with practice rather than formal training. I have a large array of diagnostic equipment that helps me in my reverse engineering challenges, but many are just luxuries or ‘time-savers’.

My need to reverse engineer PCB’s has normally been driven by the lack of OEM schematics and the presence of an expensive piece of equipment that requires repair. I have normally undertaken limited reverse engineering of a PCB in order to identify key areas of interest, in pursuit of a fault. This scenario normally results in a pile of hand drawn schematics, or partial schematics, from which I am able to diagnose the fault and its cause. In more recent cases I have reverse engineered whole PCB’s ‘for the record’ rather than just the repair. That is to say, I wanted a decent schematic as reference material for future needs, and not just the present situation. This has paid great dividends when repairing the FLIR PM Series thermal cameras that I collect and repair.

The schematic diagrams for FLIR PM series thermal cameras are protected under ITAR regulations, making it a Federal Offence for the OEM to release them to the public. My only option was to draw my own.  Having the schematics of one sample camera (the PM570) has enabled me to service and repair several others in the series with ease as they all have very similar PCB's.  If I had not properly documented the original reverse engineering work on the PM570 I would have had to repeat it on each subsequent ‘patient’. I am getting older and the memory isn’t what it used to be, so good documentation is even more important these days.

Having read this book, I realise that I am still in the ‘Dark Ages’ when it comes to documentation. I always work in pencil on paper and had not used VISIO in any part of the process. This book has shown me how useful a technical drawing package can be in producing decent documentation and also for mapping progress. The use of the layers option is an excellent idea. I already own VISIO so I will be using the techniques detailed in the book during my next reverse engineering challenge.

The reverse engineering process is well explained in the book and covers most of the techniques that I employ.  It will not make you a master ‘Reverser’ over night as that comes only with practice on a lot of different 'patients'. It does provide the knowledge that is needed to take on such a task however.  One skill that is essential in RE work is that of being methodical. Poor method and a ‘flitting’ here and there approach leads to errors, confusion and missing data. The challenge of reverse engineering a modern PCB should not be underestimated, but then it should not be feared either. Correct approach and patience will pay off. I get a real kick out of completing an RE task and then reviewing the whole 'picture' via the schematic. Some designs are things of beauty whilst others are, to be frank, 'Dogs'.

I was pleased to see that the book clearly identified the limitations that exist when reverse engineering a PCB. If a complex IC is a custom part or its ID cannot be cross referenced to a datasheet, you are basically stuffed when it comes to detailing the contents of the silicon die. As stated, however, you can treat it as a ‘black box’ and document its connectivity. It may also be possible to identify its function when the whole schematic has been drawn and live testing is carried out on its pins. The book details the challenges of the PAL, GAL, and high density programmable arrays such as those from Lattice etc. Glue logic is common on modern PCB's but does not stop the schematic making sense as the interconnectivity needs of the other IC's on the board is often understood.

Well I think I have written enough here, but if you are new to PCB reverse engineering, or even if you already have some experience, this is a great read that I am happy to recommend. It is obvious that a lot of effort has gone into writing it, and the fact that the author continues to release free additional useful material via his web site is testament to his commitment to his readers.

I hope  others will support this Gentleman's efforts by purchasing this book.

Aurora
(Fraser)

[Fraser]

Wavetek, Meterman, Fluke SF10

For info.... I spoke with the Dutch ebay seller referenced earlier and can confirm that he has sold all of his SF10 stock. This tool is a 'nice to have' and is not essential to PCB RE work. The book details alternatives such as the 'magic carpet' and 'golden finger' techniques.

If you can get your paws on an SF10 at a reasonable price I do recommend it as a very useful addition to the PCB RE tool inventory. Expect to pay around 30 Euros / $30 for one.

Aurora

[Singapura]

Hi Aurora (Fraser)

I am truly flattered by your more than excellent review of my book. I am also deeply humbled to know that someone of your engineering caliber and years of experience in this very specialized discipline (compared to your 40 years, I'm 10 years your junior!) took the time and effort to go through my book. I'm just lost for words to express my appreciation and indebtedness, because the greatest honor any reader can accord to an author is to read it from cover to cover and shower his work with high appraisal, all the more when it's to a first-time author! Never in my mind have I imagined that it would have garnered such a positive endorsement and praise from an established engineer like yourself, when I set out to write the book over a year ago. The lonely hours of labor and sweat have been worth the while!

Each time I read about your experience in PCB reverse engineering, it's like re-living part of my experience through the flashbacks of similar bits and pieces you've shared. Are we crazy or what to even consider the RE option? Most of my colleagues still think so, but there was an old engineer (about 13 years my senior) who's so intrigued when he saw my works he asked me to share my experience and teach him how to use Visio. Like you, he used to sketch the layout and schematic by hand. Since then, he had created his own collection of Visio drawings of the PCBs and power supplies which he repaired and worked on. Recently he reached retirement age (I felt kinda sad he had to go) but before leaving he told me the most enjoyable part of his 40 over years career was learning to use Visio and doing RE.

It goes to show that RE is not just for brave, young engineers, but something that is do-able (to some extent) for those who're willing to give it a try. It's definitely an enriching journey for those who've done it and will do more than give you a better appreciation for the design behind the artwork.

Cheers! 

Singapura (Keng Tiong)

[Fraser]

@Singapura,

I just tell it how it is....and your book is a great read 

I should explain that I started repairing radio's at the age of 7. I had progressed from an educational electronics 'Radionics' kit from Philips after learning all I could about transistor based circuits etc. In those days of no internet, I had no access to schematics for the radios so I had no choice but to RE the PCB's. Thankfully radios used single sided PCB's in those days and they were relatively easy 'patients' to work on. I used to either repair neighbours radios or beg scrap units from the local electronics emporium. I ended up working Saturdays for that shop when I hit my teenage years. That was how I learnt a great deal about different popular electronic components and their specifications.
I had moved on from Radios quite quickly and started to repair TV's and VCR's. That required a higher level of reverse engineering as the PCB's were more complex. I remember saving up to buy a service manual for a specific Ferguson VCR. I wanted it because it had a reputation for being one of the best written service manuals available at the time. It contained masses of background information on how the circuits worked and fault identification techniques. I actually managed to find a broken VCR of the correct model as well, so could practice the fault finding techniques on it. The VCR was a victim of a lightning 'near-miss' so was basically heavily damaged....great as a learning experience and I eventually repaired it after much effort. That service manual taught me a lot about VCR design principles and enabled me to reverse engineer other brands of units as well. I find that a prior understanding of the equipment design principles is very helpful in RE work. Computers are an obvious example of such. Once you know that a computer requires a CPU, ROM, RAM and some form of I/O, all connected via a databus and address bus, it is relatively simple to RE the heart of such a unit. It is the peripheral parts specific to the computers role that can take some decyphering !

In my professional role I was required to read schematics and to repair equipment for which no schematics were available. I was also required to design electronic solutions so I had a pretty good understanding of various equipment principles. My training as a Merchant Marine Radio Officer prepared me well as we were expected to be able to keep all the ships electronic systems working, or if not, finding a work around. A job where you have to think on your feet and sometimes invent solutions with limited resources. A great preparation for what followed in my career with the Government. I met chaps who would say that they would not attempt to repair a piece of equipment unless they had undergone the OEM training and had the service manuals.... IMHO a defeatist attitude. I would either hunt for schematics of similar equipment to give me an idea of the principles and/or RE the PCB's. There are times when OEM training is essential to avoid harm to the equipment or users of such, but I found such cases to be rare.

For me, reverse engineering PCB's was often just part of my normal repair technique and did not occur in isolation. I had to understand the circuit in order to repair it and that required RE techniques to a greater or lesser degree. I am always sad when people ask what is wrong with a circuit that has obvious 'burn-up' damage. I expect them to reverse engineer the circuit around the damaged component before asking such questions. That should tell them what the components purpose is and what may have lead to its destruction. RE is a very useful skill to have.

I have also met the 'you are mad' comments from colleagues who are overwhelmed by the thought of reverse engineering a PCB. They did not go to Maritime College though and some lack the confidence and attacking attitude that I have to such challenges.

I was known for my NASA quotes at work when a problem occurred....namely "lets work the problem and find a solution". I very much like the NASA engineers approach. Apollo 13 being a perfect example of working a problem to a successful conclusion. Giving up at the first hurdle or endless procrastination will not solve the problem !   

All the Best with the book sales

Aurora
(Fraser)

[atferrari]

I enjoyed reading this up to here! 

Not trying to compare myself with any of you both, at all, my most valid expereince doing RE was creating a partial schematic of a ??850 EPSON printer. The copies available in the Web, they are all just badly scanned ones. I was fortunate that the service manual was available, albeit poorly adpated to .pdf. 

The idea was to use both movements (printer head and cylinder scrolling) for a small winding machine.

Once I got a clear idea of the functionality (at my level of interest) I did the required surgery, by eliminating the micro in charge and the accompanying logic IC (kind of monster decoder) replacing them with a 18F452 (or maybe 18F4520).

I enjoyed the journey and learnt lot of things. BTW, I found amazing the fine details of design, some of them explained in the manual.

[Fraser]

@atferrari,

I have experienced similar challenges where the available schematics are just too poorly produced to provide useful data. Very frustrating !

I might be able to RE a complex PCB but I cannot write a program for a PIC (Yet!) 

I have just started to teach myself 'C' language programming for PIC's as that is something that I skipped over in my career, but I want to understand and practice in retirement.

The good news is that anyone with a methodical mind and a basic understanding of electronic components can RE a PCB. It just takes time and practice. Sometimes it is not even necessary to understand the functions of the VLSI chips as a fault may lie in a more basic part of the circuit such as the RESET line management or power supply.

I would not recommend trying to RE a 6 layer PCB as a first attempt though, It could get very frustrating !

Aurora

[atferrari]

@atferrari,

I have experienced similar challenges where the available schematics are just too poorly produced to provide useful data. Very frustrating !

I might be able to RE a complex PCB but I cannot write a program for a PIC (Yet!) 

I have just started to teach myself 'C' language programming for PIC's as that is something that I skipped over in my career, but I want to understand and practice in retirement.

The good news is that anyone with a methodical mind and a basic understanding of electronic components can RE a PCB. It just takes time and practice. Sometimes it is not even necessary to understand the functions of the VLSI chips as a fault may lie in a more basic part of the circuit such as the RESET line management or power supply.

I would not recommend trying to RE a 6 layer PCB as a first attempt though, It could get very frustrating !

Aurora

I abandoned learning C (difficulty in understanding pointers on the first try). Still using Assembler, currently with the 18F family.

BTW, thinking of those that you managed to repair, could you give an informal list starting with the most frequent causes of failure?  Sorry, it is pure curiosity from my part.

[Fraser]

I was considering writing a post on thermal camera repair but realised that they are little different in many ways to any other digital camera technologies. I have just retired and I am considering options for maintaining a small hobby budget income. One option is as a specialist repairer of items like thermal cameras. Most repair shops avoid such as no service information is available. I have experience of the technology and the tools for working on them. I am not a calibration centre though so I will leave that to others. I have already been offered 'casual' work in this area with significant financial incentives.
With that in mind I do not really want to go into too much detail on common faults in these technologies as that kinda puts me out of a job 

Aurora

[atferrari]

I was considering writing a post on thermal camera repair but realised that they are little different in many ways to any other digital camera technologies. I have just retired and I am considering options for maintaining a small hobby budget income. One option is as a specialist repairer of items like thermal cameras. Most repair shops avoid such as no service information is available. I have experience of the technology and the tools for working on them. I am not a calibration centre though so I will leave that to others. I have already been offered 'casual' work in this area with significant financial incentives.
With that in mind I do not really want to go into too much detail on common faults in these technologies as that kinda puts me out of a job 

Aurora

OK, no intention to ruin anyone's business. 

In fact I had in mind all the gear that you had in your hands. And, BTW, to be honest, at this very moment I have the slightest idea what a termal camera is.    From what I recall, lot of people talks about them in this forum. Have to look at to know...

[atferrari]

One is enough - moderator please delete.

[Fraser]

@atferrari,

No worries and no harm in asking 

I am not doing any repair work at this exact point in time as I need to recover from an illness but I am busy reading some great technical books and learning about PIC programming. I still have to do chores around the house as well  Sadly that leaves me little energy for 'play' in the home lab.

Best Wishes

Aurora