How to Diagnose and Fix Everything Electronic, Second Edition

Book Preface

How to Diagnose and Fix Everything Electronic, Second Edition

Everything. That’s a scary word, one I almost avoided including in the title. Can any book actually cover everything about a topic? Yes and no. Yes, in the sense that the principles and techniques you’ll learn can be applied to the repair of every kind of consumer electronics device presently being made or likely to be sold in the near future. No, in that it’s impossible to fit each of the thousands of types of components and countless varieties of gadgets in the world into one volume. Covering all of them in deepest detail would take a library, and a good-sized one at that.

The focus of this book is on today’s electronics, most of which are digital in nature, and the kinds of problems you’re most likely to encounter. In this second edition, we’ll explore some newly affordable test gear, look at ubiquitous products that weren’t so commonplace just a few years ago, cover new problems cropping up in many recent gadgets, explore automotive-related issues, go deeper into flat-panel TVs, and add helpful repair techniques and habits for more parts and devices, including condenser mics, lithium batteries, headsets and remote controls. The Glossary has lots of new goodies too.

It might seem like there isn’t that much one can service in modern digital gear, compared to the older analog circuitry. Dense boards populated by rows of chips with leads too close together even to poke at with a test probe don’t seem like good repair candidates, do they? Luckily, those areas aren’t where most failures occur, and there’s still plenty of accessible circuitry to work on! In fact, some common problems in today’s gear were rare or nonexistent in earlier technology, and they’re quite reparable.

Exotic and very obsolete components and their associated products aren’t covered in this book. Electron tubes, once the mainstay of all electronics, are pretty much gone, so we won’t spend time on their peculiarities and specific troubleshooting methods. If you want to repair tube-type guitar amplifiers, you can find books dedicated to them. Similarly, we won’t be discussing microwave ovens, which also have tubes, or transmitting amplifiers of the sort used by amateur radio operators. Nor will we take more than a passing glance at cathode-ray-tube (CRT, or picture tube)–based TVs and monitors. The CRT had a good, long run, from the 1940s until just a few years ago, but it’s a dead technology, thoroughly supplanted by flat-panel displays. Servicing CRT sets is rather dangerous, so please find a book devoted to them if you have an interest in, say, restoring antique TVs. What’s covered here is relevant but not comprehensive enough regarding that topic to keep you safe around those high-voltage beasts.

Some obsolete technology is still in common use and may remain so for at least a few more years, so we’ll explore it. Tape-based video recording continues to be used in some digital camcorders, especially at the professional and “prosumer” levels. VCRs and analog camcorders, which are rapidly disappearing as high-definition TV (HDTV) obsoletes them, may be the only key to recovery of precious home movies yet to be transferred to digital media. Serious audio devotees treasure their analog tape recorders and turntables and will never replace them with CD or MP3 players. We won’t spend much time on the old formats, but the troubleshooting techniques covered here are applicable to their repair.

Most of today’s digital equipment still contains analog circuitry for audio or video output, microphone input, voltage regulation and such. Many home theater receivers use analog amplifier stages and may have old-fashioned, linear power supplies as well, because they’re electrically quieter than newer, pulse-driven designs. In fact, the best audiophile-grade stereo gear is pretty much all analog and likely will remain that way. Even some digital radio and TV receivers use analog stages to amplify and separate incoming signals before digital decoders extract the data. So, troubleshooting techniques specific to analog circuitry are far from antiquated; they continue to be relevant in our digital era.

In this book, it is assumed that you have probably opened an electronic device at one time or another and checked a fuse. Perhaps you know a resistor when you see one, and maybe you’ve even soldered or done some basic troubleshooting. Still, we’re going to start from the top, ensuring you’re a sound swimmer before diving into the deep end. And dive we will! Beginning with a look at the tools you’ll need, we’ll explore setting up your home workshop. We’ll discuss the best types of workbenches and lamps, and where to put your gear and tools. We’ll take a close look at the most useful test instruments, where to find bargains on them, and how to operate them. Getting good with an oscilloscope is key to being a crack-shot tech, so we’ll explore a scope’s operation in detail, button by button.