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Wasting Time Checking Electronic Components?

By on April 19, 2011

If you are new in this repair field and have spent many hours checking on a circuit board and yet still could not find the fault-please do not give up. Please do not feel that you are a failure because success comes when you have failed many times. We will learn from our mistake and this will improve us on the next repair. Although you have spent countless hours without finding the bad component, do you know that during the process of checking the components, you are actually inputting lots of info? For example, how to calculate the value of the components (caps and resistors), how to desolder/resolder properly, how to scan for bad components before doing the repair work (bulged cap, burnt components, dry joints and etc), how to find the equivalent number and etc. There will be lots of things playing in your mind when you are troubleshooting  a circuit board. And each of the repair work will only make you better in the next repair.

I have made lots of mistake before reaching this level. I had been electrocuted (quite serious one-i did not use isolation transformer at that moment), shorted by primary filter cap, arc by 24 kv anode voltage and etc. I did not give up on repairing and infact i have learnt from it on how to deal with this kind of problem. We are not perfect and if you ask any electronics repairers they will surely had came across horror incident in this repair field. Don’t feel bad if you can’t locate the problem.

Take a break and relax your mind. A 5 to 10 minutes break could improve the chances of finding the fault. By the way, if you have made any mistake in electronic repair, please do share because we don’t just want to hear success stories, we would also like to know about how we have failed and rise up again to become a better repairer.



  1. miller morgan

    April 19, 2011 at 10:09 pm

    Please help and revive my dead Blue Ring tester. (I'm making a request on this page because I can't find the link to the posting page)

    My Blue Ring tester stopped working. The lights went blank and the tester would not respond to any inputs. I can guess at the cause of this problem: It's possible that the test leads were connected to a live circuit, and/or the circuit under test had a live cap and the discharge fried something in the blue ring tester. Or, it may have been something else. This happened more than a year ago, and I'm an old man and my memory isn't that good. I want to get it working again and am looking for instructions on how to troubleshoot my dead blue ring tester.

    I have the original assembly instructions and the circuit diagram but lack the know how to make sense of the schematic and to understand and isolate circuits and check them for problems.

    Any stories, links, and advice will be sincerely appreciated.

  2. Amir Mukhtar

    April 20, 2011 at 1:40 am

    Sir Jestine
    Iam going to express my feelings and experiences in above said matter with your permission.
    Sir, Thanks you again for valuable above article namely Wasting time checking electronic components.
    sir, its very important matter especially for new comers or Learners in general and particular for experience repairer.
    Actually, Diagnostics and checking components, while trouble shooting in PCB sometimes is too boring and blind, because repairer searches fault in dead equipments like a farmer. who put seed in an agricultural ground profession and than wait for seasonal harvesting.

    Although, repairing is not easy, But will be made easier by Equipment's Block Diagrams and Fault Discussions from experts, field friends and experienced repairer. So, please don't hesitate and Shy In order to Ask / Share Trouble-shooting problems and hurdles.

    By my way of thinking, Block Diagrams, Diagnostics Flow Charts, share fault problems from field experts & Training Teachers and Circuit Diagram is the best and easiest way to Learn, check and troubleshoot any type of electronic equipments.
    Also, Use internet in positive way to get best technical knowledge from it.

    Thanks you
    Amir Mukhtar
    A Small Student of Sir Jestine.

  3. admin

    April 20, 2011 at 3:46 am

    HI Amir,

    Thanks for the good comment!


  4. admin

    April 20, 2011 at 3:51 am

    HI Miller,

    From my experience if the blue ring tester can't be turned on usually either one of the IC have problem (assuming you have check or replace the battery). The ICs is easily found from the market. You may also visit the forum link for more information:


  5. Waleed Rishmawi

    April 20, 2011 at 4:18 am

    when I started my repair work in my shop about 10 years ago, I did not know anything about put the parts back in their place on board. for expample. I could locate a bad transistor and I get the part for it but very often, the tv will not work and I spend a lot of hours trying to find out what the cause of the problem. I call my friend to help me out to realize that the transitor that I put back on board was put in reverse position and that is why the tv did not work..
    other time I could remember the first time I replaced a capacitors on borad..again, back wards and some of them exploded in my face..I was wearing protecting glasses ( I always do)and saved my eyes from that flying capacitors..I did a lot of mistakes in my career..but thank God I started paying attention...things got better. I look back where are I was and where I am now, I thank God for everthing.

  6. beh

    April 20, 2011 at 5:12 am

    you said your blue ring is dead this could be by a simple problem like battery

    check your 9 volt battry with your voltmeter you should get at least 8-8.5 volt dc
    and then check the wire black and red of your blue ring that goes to battery they must be good when you ck them by ohmmeter
    and must be attched by good solder to pcb ck and tell me

  7. admin

    April 20, 2011 at 7:57 am

    HI Waleed,
    Thank God for the goggles! My friend have asked me whether i want to wear contact lens or not and i told them that i preferred spectacles. Installing components the other way round also a problem for beginners.


  8. randy

    April 20, 2011 at 11:14 pm

    Thank you very for the encouragement. There are really times that you can not pinpoint the fault immediately when troubleshooting electronic equipments. And have lots of mistakes too. In my part, when I repaired my cousin's black and white television before, I checked the board and found out that it has a blown fuse and the surge limiter resistor opens. I replaced the two components and turned the power on. Suddenly the set caught fire and I saw with my two eyes that the fire rapidly eats one leg of the rectifier diode. I turned off the set immediately and check what's the cause of the fire. I found out that it was the fuse. the original fuse rated 2 amperes but I replaced it with 2.5 amperes. I overlooked the .5 amperes that makes the set to caught fire. In this experience, we must be very careful on replacing any components in any electronic equipments.

  9. admin

    April 21, 2011 at 3:21 am

    HI Randy,

    An extra of.5 amp could cause the set on fire! I hope the readers will this advice and only replace with the same rating of fuse. Thanks for sharing!


  10. Waleed Rishmawi

    April 21, 2011 at 3:47 am

    Wasting time is think it is over rated. I call it investment. it might take me a whole week to find out the problem but next time I deal with this kind of problem, It will not take me that long.
    what I do in my shop, is I write in my note book the discription of the problem along with the equipment brand name and model number and the problem. then I disripe what I did to slove that problem. that way the next time I know what is right to fix the problem. it might take me an exta time to do that but in the long run, it is saving me a lot of time..a time well spent.

  11. admin

    April 21, 2011 at 3:56 am

    HI Waleed,

    The right word is Investment. I wrote that post because i do not want the beginners to thinks that if it can't locate the fault it will be a waste of time to them. I want them to think the positive side.


  12. beh

    April 21, 2011 at 5:44 am

    ok yes as i told you it was battry i am happy you fixed your blue ring
    and it work for you again

  13. Wahab

    May 8, 2011 at 3:00 am

    Hi, I was working on a faulty AVR of my diesel Generator. Some of its components leads were wasted due to rust and its stud diode and thyristor found shorted. I replaced all defective components and tried. Its Thyristor bowed again. On further checks one of Zener leads found broken due to rust and the nearest resistor also found overheated. This Zener is supplying to a UJT used for firing circuit of thyristor via a pulse transformer. Now I need to now
    1. What could be the voltage rating of Zener.
    2. What is the use of a second firing supply via a relay.
    Your kind help may resolve my circuit problem.

  14. admin

    May 10, 2011 at 3:34 am

    HI Wahab,

    In that kind of situation we really need a schematic and without it will be hard to locate the value. We need the circuit to understand how this firing supply via relay work.



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