Free pdf download diagnose everything electronic

Cyanoacrylate Glue Also known by the trademarks Super Glue and Krazy Glue, instant adhesive can be useful on some plastic parts.

This type of glue is handy for holding things together while you fasten them with other, more permanent means. Just be aware that it outgases a white film as it hardens that is tough to remove, so keep it away from lenses, display screens and other surfaces where that might be a problem. While it might seem primitive to blast parts instead of scoping their signals, doing so can save you hours of fruitless poking around when circuits wig out only after they warm up.

Data Books Although the Internet offers lots of great service-related information, some important tidbits are still more easily found in a good old data book. So is pinout data for various ICs, voltage regulators and varieties of transistors. At the least, consider getting a transistor substitution book.

Parts Assortment Having a supply of commonly used components is quite handy. Plus, your stash will be hit-ormiss, with big gaps in parts values.

Consider buying prepackaged assortments of small resistors and capacitors or going to a hamfest and stocking up for much less money. Resistors and capacitors, luckily, almost always have standardized markings, and you can easily measure them if you have the appropriate meters. If you do run into a suspicious one, you can pull its replacement off a scrap circuit board. Instead, focus on resistors, transistors, voltage regulators, fuses and, especially, electrolytic capacitors.

The higher the ratings, both capacitive and voltage, the larger the cap. Stocking up on transistors is tricky because there are thousands of types. Get some 2NA or equivalent, along with some 2N You may find hamfest bags of parts with similar numbers that start with MPS or other headers.

Diodes and rectifiers are frequent repair issues, so it pays to have some on hand. The only difference between a diode and a rectifier is how much power it handles.

Small-signal parts are called diodes, and larger ones made for use in power supply applications are dubbed rectifiers. Look for 1N and 1N for the small fry, and 1N through 1N for the big guns. The bridge rectifier, which integrates four rectifiers connected in a diamond configuration into one plastic block with four leads, is commonly used in power supplies.

Get a few with current ratings in the 1- to 5-amp range and voltage ratings of to volts. To house components, most of us use those metal cabinets with the little plastic drawers sold at hardware stores. Sort resistors and capacitors by value. If you have too many values for the number of compartments in the drawers, arrange the parts into ranges.

Once you learn to read the color code see Chapter 7 , plucking the part you need from its drawermates is easy. Scrap Boards for Parts Despite what I said about stripping old boards, you do want to collect carcasses for parts. An old VCR or radio can provide a wealth of goodies, some of which are not easily obtained at parts houses, especially at p. The better approach is to remove circuit boards, knobs and anything else that looks useful, and scrap the rest. If the leads are too short, solder on longer ones.

Wish List For most service work, you can easily live without the following items, but they make for good drooling. Some advanced servicing requires them, but not often.

Inductance Meter This meter reads the inductance value of coils, which seems like something quite useful, right? Usually, the coil will open cease being connected from end to end from a melted spot in the wire, as a result of too much current overheating the windings. In the high-voltage coils used in CRT TVs and LCD backlighting circuits, insulation between coil windings can break down and arc over, causing a short between a few windings but leaving most of them intact. Logic Analyzer An offshoot of the oscilloscope, a logic analyzer has lots of input channels but shows only whether signals are on or off.

It is used to observe the timing relationships among multiple digital signal lines. Getting benefit from it requires knowledge of what those relationships should be, information rarely provided in the service manuals of consumer electronics devices. SMT stuff is somewhat hard to work on, thanks to the size scale and the lack of holes to secure a part while you solder it. SMT rework stations are expensive and not hobbyist material, at least so far. Spectrum Analyzer This is a special type of scope.

Instead of plotting voltage versus time, a spec-an plots voltage versus frequency, letting you see how a signal occupies various parts of the frequency spectrum. Used extensively in design and testing of radio transmitters, spec-ans are expensive overkill for most service work, unless RF is your thing. Chapter 3 Danger, Danger! Even some battery-operated devices step up the voltage enough to zap the living crud out of you. That said, you can learn to navigate all kinds of repairs safely.

Electric Shock This is the most obvious hazard and the easiest to let happen. It might seem simple to avoid touching live connection points, but such contact happens all the time, because the insides of products are not designed for safety. You may find completely bare, unprotected spots harboring dangerous voltage, and a slip of the tool can be serious. Remove your wristwatch and jewelry before slipping your hand into a live electronic product.

Yes, even a battery-operated one. Take off the wedding ring, too. This is where old electrons go to die after having done their work, wending their way through the various components to get there. The trick is not to let them take you along for the ride! If you are in contact with the circuit ground point and also a point at a voltage higher than about 40 or 50 volts, you will get shocked. If your hands are moist, even lower voltages can zap you.

The bodily harm from a shock arises from the current number of electrons passing through you, more than the voltage their kick itself. The path through your body is important as well, with the most dangerous being from hand to hand, because the current will flow across your chest and through your heart.

Always wear shoes. Switching power supplies see Chapter 14 have part of their circuitry directly connected to the AC line. Once again, never work on circuitry while it is directly connected to the AC line. Lots of AC-operated products have exposed power supplies, with no protection at all over the fuse and other items directly connected to the AC line.

Touching one of those parts is no different than sticking a screwdriver in a wall socket. I like to use a piece of soft vinyl cut from the cover of a school notebook. Capacitors, especially large electrolytics, can store a serious amount of energy long after power has been removed.

The only way to be sure a cap is discharged is to discharge it yourself. Never do this by directly shorting its terminals! The current can be in the hundreds of amps, generating a huge spark and sometimes even welding your tool or wire to the terminals.

Instead, connect a ohm resistor rated at a watt or two to a couple of clip leads, and clip them across the terminals to discharge the cap a little more slowly.

Keep them connected for 20 seconds, and then remove one and measure across the cap with your DMM set to read DC voltage. It should read zero or close to it. If not, apply the resistor again until it does. Before discharging a cap, look at its voltage rating, because the voltage on it will always be less than the rating.

Most of the time, low-voltage caps are in parts of circuits that cause the capacitors to discharge pretty rapidly once power is turned off, but not always. The capacitance value tells you how much energy the capacitor can store.

CRTs, especially in color TV sets, act like capacitors and have low enough leakage to store the high voltage applied to their anodes the hole in the side with the rubber cap and the thick wire coming from it for months. Just be very, very careful if you do. The terminals at the back of the tube carry some pretty high voltages too. The backlighting circuits of LCD monitors and TVs, along with much of the circuitry of plasma TVs, operate at high enough voltages to be treated with respect.

Physical Injury The outsides of products are carefully designed to be user-safe. Not so the insides! Move deliberately and carefully; quickly shoving a hand into nooks and crannies leads to cuts, bleeding and cursing.

Video projectors use lamps so bright that you will seriously damage your vision by looking directly at them. An exploding lamp goes off like a little firecracker, oh-so-expensively showering you with fine glass particles and a little mercury, just for extra effect. Excess component leads clipped with diagonal cutters have an odd, almost magnetic tendency to head straight for your corneas at high speed. Solder smoke also likes to visit the area, and it can be pretty irritating.

You can hurt your ears, too, particularly when working on audio amplifiers with speakers connected. Touching the wrong spot may produce a burst of hum or a squeal loud enough to do damage when your ears are close to the speakers. That sort of thing happens mostly with musical instrument amplifiers, because their speakers are right in your face when you work on them, and those amps pack quite a wallop.

Even a 15watt guitar amp can get painfully loud up close. Other opportunities for hearing damage involve using headphones to test malfunctioning audio gear. Even a little MP3 player with just a few milliwatts thousandths of a watt of output power can pump punishingly loud noises into your ears, particularly when ear buds that fit into the ear canals are used. If you must wear headphones to test a device, always use the over-the-ear type, and pull them back so they rest on the backs of your earlobes.

Keep your face away when spraying. When you must get close while soldering, holding your breath before the smoke rises can help you avoid inhalation. Your Turn Sure, electronics can hurt you, but you can hurt the equipment too. It was pretty hard to damage a vacuum tube circuit with anything short of a dropped wrench hitting the glass.

Here are some ways you can make a mess of your intended repair. Electrical Damage Working with powered circuits is essential in many repair jobs. Poking around in devices with power applied, though, presents great opportunity to cause a short, sending voltages to the wrong places and blowing semiconductors, many of which cannot withstand out-of-range voltages or currents for more than a fraction of a second.

One of the easiest ways to trash a circuit is to press a probe against a solder pad on the board, only to have it slip off the curved surface when you look up at your test instrument, and wind up touching two pads at the same time.

Staying Safe 35 Any time you stick a probe on a solder pad, be very aware of this potential slip. Luckily, many times it causes no harm. Alas, sometimes the results are disastrous. It can be helpful in tight circumstances to cut a small square of electrical tape and poke the end of the probe through it, thus insulating the ground ring. When operating a unit with your bench power supply, there are several things you can get wrong that will wreck the product.

Nothing pops IC chips faster than reversed polarity. Products subjected to it are often damaged beyond repair. Some devices, especially those intended for automotive use, have reverse-polarity protection diodes across their DC power inputs.

If the power supply has a lot of current available, the diode may rapidly overheat and short, requiring its replacement, but the rest of the unit should remain unharmed. Few battery-operated products have protection diodes.

So, be very careful to connect your power supply the right way around, and never hook it up while power is turned on, lest you even momentarily touch the terminals with your clips reversed.

A decade ago, most items ran on unregulated linear-type adapters and did the regulating internally, so they were fairly tolerant of having excessive voltage coming in, and you were fine if you were within 2 or 3 volts.

These days, more and more products are using regulated, switching-type AC adapters with very steady voltage outputs, so the gadgets expect a pretty accurate voltage. That can be an effective diagnostic technique in some cases, but it should be used with caution because you can pull too much current through some other component and blow it. That, too, can be useful, but it requires consideration of the correct voltage and polarity, the amount of current required, and exactly where that energy will go.

When your scope is set to AC coupling see Chapter 6 , it inserts a capacitor between the probe and the rest of the scope. After you probe a point with a DC voltage on it, that voltage remains on the capacitor and will be discharged back through the probe into the next point you touch.

When using AC coupling, touch the probe to circuit ground between measurements to discharge the cap and prevent damage to delicate components.

One of the easiest is to tear a ribbon cable or snap off a critical part while disassembling the device. Some products pop apart easily but may have hidden risks. I once serviced a video projector cleverly designed to snap open without a single screw, but a tiny ribbon cable linked the top and bottom, and I was lucky that it popped out of its connector without being torn in half when I removed the top case.

Small connectors of the sorts used on laptop motherboards and pocket camcorders can be torn from the circuit board. A little too much pressure when you disconnect the cable, and the connector can come right off the board. Depending on the size scale of its contacts, it may be impossible to resolder it.

Most ribbon connectors have a release latch you must flip up or pull out before removing the ribbon. Always look for it before pulling on the cable. See Figures and Your soldering iron, that magic instrument of thermo-healing, can also do a lot of damage, especially to plastic. One common error resulting in an unsafe repair job is neglecting to put everything back the way it was. In units with lots of wires, it can happen, despite your best intention to be careful.

For one thing, you may have created a short or a lack of insulation that could cause damage or injury when power is applied. For another, you might forget later and close the unit up in that condition. Patching melted insulation can be as easy as remelting it to cover the wire, in the case of low-voltage, signal-carrying wires with only small melted spots.

Or it might require cutting, splicing and heat-shrink tubing if the wire handles serious voltage, or if the damage is too great. Remember, electrical tape will come off after awhile, so never depend on it for long-term safety. Older stereo amps and receivers, for instance, sometimes require bias adjustments when the output transistors are changed.

Let it run on the bench for a few hours at normal listening volume and see how hot it gets. When the product has an AC cord, take a look at it and run your hand along its entire length, checking for cuts. Naturally, you want to live, so unplug it before doing this!

Replace the cord or repair it as seems appropriate for its condition, paying extra attention to a good, clean job with proper insulation. With a damaged AC cord, I like to use both electrical tape and heat-shrink tubing over it. Chapter 4 I Fix, Therefore I Am: The Philosophy of Troubleshooting I magine if your doctor saw you as a collection of organs, nerves and bones, never considering the synergistic result of their working together, supplying each other with the chemicals and signals necessary for life.

No organ could survive on its own, but together they make a living, breathing, occasionally snoring you! The knife is right there next to the body, but anybody on earth could have done the crime. Why was the victim killed? Who knew him? Who might have wanted him dead? Troubleshooting, which involves skills somewhat like those of doctors and detectives, is a lot like that. To be a top-notch tech requires consideration of the bigger picture. Who made this product, and what were the design goals?

How is it supposed to work? How do various sections interact, and what is the likely result of a failure of one area on another? Machines are systems. Being built by humans, they naturally reflect our biological origins, with cameras for eyes, microphones for ears, speakers for larynxes and microprocessors for brains.

Even the names of many parts sound like us: tape recorders, hard drives, and optical disc players have heads, turntables have arms, chips have legs and picture tubes have necks.

Some products even exhibit personalities, or at least it feels that way to us. Their features and quirks can be irritating, humorous or soothing. The more you come to understand how devices work at the macro level, the more sense their problems will make. The more you can consider products as metal and silicon expressions of human thinking, the better sleuthing skills you will attain. Why Things Work in the First Place When you get a few thousand parts together and apply power to them, they can interact in many ways.

I remember a ham radio transceiver whose digital control system exhibited a bizarre, obscure behavior in its memory storage operation that no other radio of that model was reported to have, and I never found any bad parts that might explain the symptom. I finally had to modify the radio to get it to work like all the others. Sure, you string a few gates together and you will be able to predict their every state.

Get a few thousand or more going, run them millions of times per second, and mysterious behaviors may start to crop up. As the current trickles through them, it is used to do work, be it switching the gates in a microprocessor, generating laser light for a disc player, or spinning the disc.

Electrons, though, are little devils that will go anywhere they can. The designer has carefully considered all the possible paths and correctly engineered the circuit to keep those pesky electrons moving along only where and when they should, locking out all possible behaviors except the desired one.

When choice arises, through failing components, user-inflicted damage or design errors, the electrons go on a spree like college students at spring break, and the unit lands on your workbench. Products as Art A machine is an extension of its designer much as a concerto is an extension of its composer. In this case, however, they tend to have unifying characteristics more reflective of their manufacturing companies than of a specific person.

The layouts, the styles of capacitors, the connectors, and even the overall look of the copper traces on a board are different and consistent enough to be dead giveaways.

Perhaps it had an ear microphone , some memory recording tape and a mouth speaker. Each system did its simple job, with support from a stomach power supply and some muscles motors, amplifiers. What was missing was a brain. Gone are simple mechanical linkages to control sequencing and movement of mechanisms. Instead, individual actuators move parts in a sequence determined by software, positional information gets fed back to the microprocessor, and malfunctions might originate in the mechanics, the sensors, the software, or some subtle interaction of those elements.

No longer are there potentiometers variable resistors to set volume or brightness; buttons signal the brain to change the parameters. Failures in these areas can be tough to trace, because their incoming signals from the computer chip are dependent on tricky timing relationships between various signal lines.

This is a profound shift from the old way of building devices, and it adds new layers of complication to repair work. Some offer updatable software, while many have the coding hardwired into their chips. Which would you like to be today: surgeon or psychiatrist? The screws will be stripped, or there will be poorly soldered joints with splashes of dripped solder lying across pads on the board.

Wires may be spliced with no solder and, perhaps, covered in cellophane tape, if at all. Adjustments will be turned, insulation melted, and so on. In a word: sloppiness. That might sound exaggerated, but I used to run into it a lot when I worked in repair facilities. Um, right, Sony used Scotch tape to join unsoldered wires. Sure, buddy. I remember one incident in which I refused to repair a badly damaged and obviously tampered-with shortwave radio. The owner was so angry that he called my boss and tried to have me fired!

The boss took one look inside the set, clapped me on the back, laughed, and told the guy to come pick up his ruined radio and go away.

The key to performing a proper, professional-quality repair job is meticulous attention to detail. Mistakes Beginners Make Beyond sloppy work, beginners tend to make a few conceptual errors, leading to lots of lost time, internal damage to products, and failure to find and fix the problem.

Here are some common quagmires to avoid. Adjusting to Cover the Real Trouble Analog devices often have adjustments to keep their circuit stages producing signals with the characteristics required for the other stages to do their jobs properly.

TVs and radios are full of trimpots variable resistors , trimcaps variable capacitors and tunable coils, and their interactions can be quite complex. Power supplies usually have voltage adjustments, for instance, and earlier-generation CD players were loaded with servo adjustments to keep the laser beam properly focused and centered on the track. Even a digital media receiver may have tunable stages in its radio sections.

It can be very tempting to twiddle with adjustments in the hope that the device will return to normal operation. It never causes drastic changes in performance. Messing with the adjustments will only get you into trouble later on when you find the real problem, and now the machine really is way out of alignment, because you made it that way. Leave those internal controls alone! In some cases, close is good enough. In others, slight misadjustments can seriously degrade circuit performance.

I once worked on a pair of infrared cordless headphones with a weak, distorted right channel. After some testing, it was clear that the transmitter was the culprit, and its oscillator for that channel had drifted off frequency. A quick adjustment and, sure enough, the headphones worked fine for a little while. Then the symptom returned. The real problem: a voltage regulator that was drifting with temperature.

Luckily, readjusting the oscillator was easy after the new part was installed. When multiple adjustments have been made, it can be exceedingly difficult to get them back in proper balance with each other. Making the Data Fit the Theory Most techs have been guilty of this at some time.

You look at the symptoms, and they seem to point to a clear diagnosis—all except for one. Trust me, it is, and you are about to embark on a long, frustrating hunting expedition leading to a dreary dead end. It was right in front of me from the start! Nobody needs glasses for that. When addressing symptoms creates more symptoms, take it as a strong hint that you are on the wrong track.

These digital days, circuitry is much more reliable than in the old analog age, yet modern gear often has a much shorter life span. How can both of those statements be true? But with so much more going on, they include complicated power supplies and a multitude of connectors and ribbon cables. Plus, some parts work much harder than they used to and wear out or fail catastrophically from the stress.

And thanks to the rapid pace of technological change, the competition to produce products at bare-bones prices and the high cost of repair versus replacement, extended longevity is not the design goal it once was. Contrary to popular myth, nobody deliberately builds things to break. It may seem like electronic breakdowns are pretty random. Some part blows for reasons no one can fathom, and the unit just quits.

Oh, sure, when you make millions of chips, capacitors and transistors, a small number of flawed ones will slip through quality control, no matter how much testing you do. Much more often, products fail in a somewhat predictable pattern, with a cascading series of events stemming from wellrecognized weaknesses inherent in certain types of components and construction techniques.

In other words, nothing is perfect! Infant Mortality This rather unpleasant term refers to that percentage of units destined to stop working very soon after being put into service. Imperfect solder joints, molecular-level flaws in semiconductors and design errors cause most of these. Typical infant mortality cases crop up within a week or two of purchase and land in a warranty repair center after being returned for exchange. Or perhaps the seller refuses to accept it back, and you get stuck with a brand-new, dead device you want to resurrect.

Mechanical Wear By far, moving parts break down more often than do electronic components. Hard drives, VCR and camcorder mechanisms, disc trays, laser head sleds and disc-spinning motors are all huge sources of trouble. Bearings wear out, lubrication dries up, rubber belts stretch, leaf switches internal position-sensing switches bend, nylon gears split, pet hairs bind motor shafts, and good old wear and tear grind down just about anything that rubs or presses against anything else.

Connections Connections are also mechanical, and they go bad very, very often. Suspect any connection in which contacts are pressed against each other without being soldered. That category includes switches, relays, plugs, sockets, and ribbon cables and connectors. The primary culprit is corrosion of the contacts, caused by age and sometimes, in the case of switches and relays, sparking when the contacts are opened and closed.

Also, a type of lubricating grease used by some manufacturers on leaf switches tends to dry out over time and become an effective insulator. See Figure At one time, a dual-layer board, with traces on both sides, was an exotic construct employed only in the highest-end products. Today, dual-layer boards are pretty much standard in larger, simpler devices, while smaller, more complex gadgets may utilize as many as six layers! The problems crop up in the connections between layers.

Those connections are constructed differently by the various manufacturers. The best, most reliable style is with plated-through holes, in which copper plating joins the layers. As boards have shrunk, plated-through construction has gotten more difficult, resulting in a newer technique that is, alas, far less reliable: holes filled with conductive glue. This type of interconnect is recognizable by a raised bump at the connection point that looks like, well, a blob of glue see the translucent glue over the holes in Figure Everything Books.

How to Diagnose and Fix Everything Electronic shows you how to repair and extend the life of all kinds of solid-state devices, from modern digital gadgetry to cherished analog products of yesteryear.

You'll start by selecting the tools and test equipment you'll need and setting up your workbench. Then, you'll get familiar with components and how they form circuits, stages, and sections of a device. Next, you'll learn how to take a product apart, figure out what's wrong with it, replace components, and reassemble it. Just click on the icon and read the articles that interest you at any convenient time. Read also. Total Comments: 0. Sign in:. Click here to download Wait You will be directed to the download link after the count has ended.

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