Diagnosing circuit board?

[mcostello]

I have almost no electrical experience, I can (usually) diagnose house and some Auto problems. Could someone point me where to get started in learning how to diagnose circuit boards. Have to start somewhere. Thanks.

 

[canadianhorsepower]

I have almost no electrical experience, I can (usually) diagnose house and some Auto problems. Could someone point me where to get started in learning how to diagnose circuit boards. Have to start somewhere. Thanks.

what is your goal??

 

[Tin Falcon]

What is it you are trying to fix?
do some Google research on that item.
I usually start on the power supply section of the board.
check fuses, diodes /rectifiers and mosfets in that order.

control boards often have opto isolation chips that protect the other circuits.

open ended questions are hard to answer bud.
Also Check the electronics forums unless the board is specific to machining.
Tin

 

[mcostello]

Can anyone recommend a beginning Electronics forum? Not machining related, but I like the forum here, it's like a trusted friend usually civil and knowledgeable. Pendulem clock stopped and it's almost new, would like to attempt repair,but it's OT here.

 

[canadianhorsepower]

Can anyone recommend a beginning Electronics forum? Not machining related, but I like the forum here, it's like a trusted friend usually civil and knowledgeable. Pendulem clock stopped and it's almost new, would like to attempt repair,but it's OT here.

send me a private email and will email you a bok back.
can't post it here cause it's to big
cheers

 

[Bluechip]

Can anyone recommend a beginning Electronics forum? Not machining related, but I like the forum here, it's like a trusted friend usually civil and knowledgeable. Pendulem clock stopped and it's almost new, would like to attempt repair,but it's OT here.

This may be useful for tutorials.

http://www.electronics-tutorials.ws/

One forum I'm on, for microcontrollers in my case, but it does have a beginners section IIRC

http://www.electro-tech-online.com

Electronics is very much a 'paws on' pastime. If you consider you won't get very far without an oscilloscope etc. it gets quite expensive.

But, it is do-able. I suggest you start with Ohms Law, some resistors and a Multimeter.

Best of luck ... Thm:

Dave BC

 

[canadianhorsepower]

I have almost no electrical experience, I can (usually) diagnose house and some Auto problems. Could someone point me where to get started in learning how to diagnose circuit boards. Have to start somewhere. Thanks.

go to the download section I just put a book
enjoy

 

[proace]

It is always good to learn something and electronics is great. Don't know what your working on but troubleshooting a circuit board can be a major undertaking. I know, I was in avionics for many years.
If the circuit board happens to be something you need now I would suggest doing a search for your local amatuer radio club. There you can most likely find someone to help and show you how to fix it, most likely for free. If you are just wanting to learn then those guys are a great resource when you have questions.

 

[Lakc]

Ill second what Proace says, Ohio has a large fraternity of ham radio folks and they are very helpful.

 

[Banjoe]

canadianhorsepower - I have to lodge a small complaint about your efforts. The excellent book that you posted will now take up time that I should be spending on other hobbies so I'm going to have to stop showing up at the office every single day of the week like the boss expects or doing yard work as the real boss expects. : ^ )

Much appreciated.

Joe

 

[Engineeringtech]

As an electronic tech with over 35 years experience I would not recommend learning electronics to troubleshoot one board, unless you are going to do a lot of it. If you can't find someone to troubleshoot it for you, consider that most problems are dirty switch contacts, dirty or intermittent pots, blown fuses, over heated / burnt components. You can check all these things before you start doing a signal analysis.

 

[mcostello]

thanks, I was doing good until the words " signal analysis" popped up.;D

 

[Engineeringtech]

thanks, I was doing good until the words " signal analysis" popped up.;D

Sorry. I did not mean to muddy the waters. Electronic equipment can be very complex, or very simple. I don't know your background, or how familiar you are with electronic components. It is very difficult to communicate a troubleshooting approach over the internet, phone, etc. to another experienced tech, let alone a novice. And frankly, I wasn't offering to do long distance troubleshooting for you, because my time is also valuable. I spent many years learning my trade. I was merely trying to say there are usually things you can check yourself before you involve a tech or repair service.

For the record, "Signal Analysis" usually involves injecting a signal (or signals), and looking at the output (with a O-scope, DMM, spectrum analyzer, etc.) You can do a lot of troubleshooting before you get to that stage. Generally, with any electronic circuitry, you have inputs and outputs. The inputs might be switches, pots (like the volume controls on old audio equipment) or sensors. They might also be a digital signal from a control panel. Outputs might be digital readouts, drive motors, electromagnets, and valves for air cylinders. If you have a sense for how the circuit is supposed to act while it is functioning correctly, that often helps you narrow the problem down. For instance, if the motor isn't running, you can trace the motor wiring back to the board, to see if you have a loose connector or connector pins. Was there any smoke before the board failed? Look for burn marks on components, especially relays, power transistors, etc.. Are LED's and light bulbs supposed to be lit when the circuit is on? You might not have any power to the circuit. Look for a power supply (wall transformer, brick, open frame supply) Is a fuse on the supply blown? Sometimes you can substitute another component, like wall transformer to see if that is the issue. If a switch is dirty, and not making contact, cleaning it with switch contact cleaner might do the trick. If you look at the backside of the circuit board and see a solder connection that is grey, or an obvious loose connection or broken wire, all you might need is some solder and a soldering iron.

Much of today's computerized equipment does not have mechanical switches, pots, and etc. That makes it much harder to troubleshoot. (In my opinion.)

I am not familiar with pendulum clocks, but I assume the pendulum regulates the clock speed. I would start with a thorough search to learn the operating principles of an electromechanical pendulum clock. I'm guessing an electromagnet (or solenoid) is pulsing (attracting) the pendulum at a precise time determined by an optical sensor. If, for instance, you blocked the sensor, and put a screwdriver blade near the electromagnet, you would know if it is operating.

That's all the advice I have for you right now. Best advice is to find out how the equipment is SUPPOSED to operate.

 

[peynir]

@mcostello, Diagnosing issues in electronics might seem very difficult for some but all it needs is practice and with practice you start understanding better and your guesses about what the problem might be improve and get accurate. You need to closely inspect the PCB before anything to see if there are any blown components such as fuses or caps etc. The first step is obviously checking all the connections to see if they are working fine. Then the power-on diagnostics, which show if the device is getting powered up or not. If it isn’t, check the power circuit. After this step, start checking where you PCB is malfunctioning and from this point onwards your diagnostics get application specific.

 

[mcostello]

I have built a pulse EDM from Ben. It is at SIL waiting to be double checked before I power it up and test output points. He has suddenly got very busy and I don't know when He can get to it. I make small parts for a customer and this machine would help with that. I still need to make the rest of the machine to go along with it. I am wanting to use it and get along with things but, OH WELL. Will keep everyone posted as to progress. Thanks for the help.