I came across quite a number of questions about electronic circuit schematics diagram.
Most of the question asked are:
a) Do we really need a schematic diagram in order to repair any electronic equipment?
b) Will schematic diagram help us to repair faster?
c) At where we can get a particular schematic diagram?
d) How to read schematic diagram?
Well, the answers is as below:
a)-Theoretically yes, practically not necessary, it all depends on how good you are in electronic repair knowledge. For a beginner it is a 'must' for you to understand about schematic diagram, as you gradually gained more knowledge you will automatically depends less on schematic diagram. You will definitely need a schematic diagram when you come across a new designed or technology. For example, when comes to crt monitor repair i seldom see schematic because i already understood most of the circuitry and section in a crt monitor. The new technology such as lcd or tft monitor makes me have to temporarily relies on schematic diagram. As my knowledge of lcd monitor repair grows, i will gradually depends less on the schematics. May be my situation is different from yours because I'm concentrating only on one type of equipment. I've seen quite a lot of repairers in my country that repair many types of equipment such as tv, video, vcd, dvd, amplifier, hi-fi, fax, laser printer, microwave and so forth. Most probably they need schematic diagram to keep them up to date on each of the equipment technology.
b) If you have a particular schematic diagram for that particular equipment, your troubleshooting time can be reduced to half! Unfortunately many manufacturer do not release their equipment's schematic diagram. If you depends on too much of schematic you will be stuck on how to repair that particular equipment. Why with schematic diagram you can repair any equipment faster? Because a schematic diagram shown you all the part list, waveform, voltages, explanation how that particular equipment work, block diagram, schematic design, component's part number, electrical schematics symbols, substitution, modification (if have) and electronic schematic symbols and etc. Assuming you have a power supply section blown and you could not recognize the component part number, but with schematic you will be able to find the exact part number and finally repaired the equipment.
c) If you work in the equipment's factory or their distributor you will have the schematic diagram for the model that they sell. Any under warranty unit that comes in you will be able to diagnose and repair the equipment fast. This will increase the company's reputation and customers will recommend to their friends about the quick service of that particular brand of equipment. You also can get schematic diagram in the form of a book from local electronic shops. This is usually a compilation of few brands and model of a specific electronic equipment. Tv or television schematics diagram are easily to get but computer monitor schematics and radio amplifier schematics is a little bit harder to find. If you have the budget get one of the book. Third, as most of us already know that you can download free electronic schematics diagram from the internet. Free tv schematics is easily found on the internet. You may also buy it the 'CD' format. This investment will usually pay back in the shortest time.
d) As how to read schematic diagram, I'm unable to show you thru article because you do need a real schematic diagram in order to make you understand. Reading schematic is not that difficult, provided you have some basic electronic knowledge. I have a few suggestions:
-Ask from a friend who is in the repair line
-Take short courses on electronic repair and ask the lecturer
-Buy books from your local bookstore about the subject "how to read schematic diagram"
-Buy schematic diagram and learn on your own (this will take sometimes but worth it)
-Fix some project kit using the electronic kit schematics given. This will add to your knowledge also.
Conclusion-In order to become a successful electronic repairer you must understand how to read schematic diagram.
