Monday, August 23, 2010

Do it yourself Flyback Tester


As a technician there are test equipment that one requires to get started in electronics which are assumed to be obvious in order to get started in your repair work may it be for hobbyist or professional purposes.

Among them they are others which are not taken seriously as a starter kit but as you walk down the road you find it necessary to add them on your work bench.

When this need arises the technician has an option to go shopping for one or decide to do it by him or herself.

I would like to address the latter group which decides to do it themselves. Although most people would prefer to go this route, you realize that very few people can access the printed circuit board facility around them and hence become difficult for them to get started.

In this article I am going to show you how you can go round this problem by using readily available vero board and achieve the same result like the machine printed circuit board.

As a starter kit (D.I.Y) I have done a template using strip board of the flyback tester based on circuit diagram found on the internet and its working wonderfully for me.



Component values are recorded on their body. Resistors, capacitor, ics , transistors etc for ceramic capacitors the number is written on the body. For ics I advice to use ic sockets instead of soldering them directly to the circuit board.














Testing Degausing Coil-Only 3 LEDs ON.



What is this simple tester capable of doing:-

1. Testing primary winding of flyback transformer in circuit.

2. Testing horizontal yoke coil in crt television /monitors.

3. Testing primary winding of switch mode power supply(all) in circuit

4. Testing the degaussing coil winding in crt television/monitor

5. Testing small DVD motors like the spindle motor ie 2 led lights.

Challenges: as you can see i had a problem of getting a good housing for my project, electronics shops here in my town don't seem to store them therefore i decided to use one of the junk analogue meter housing to serve the purpose.

Feed back: i would love to hear feedback from you fellow technician about your experience on this simple but very important workbench tool.


Additional information for the do it yourself fly back tester

For those who like to use the 9 Volt battery for the power supply please use this adapter to get the 6 Volts for the circuits.





Thank you guys

Let meet in the next class.

Humphrey Kimathi
Author CRT Television repair course





33 comments:

  1. HI Humphrey,

    Congratulation! You have done a great job in creating a repair blog. I have set two resolutions for this year and one of them will be ready in a month's time. The other one will take another 3 months to complete. There was a saying "A vision without action means nothing but a vision with action you can move the world"

    The vision is not necessary have to be in the repair line. It can be any thing.

    Consistently provide more info in this blog and I'm sure you will have lots of faithful readers.


    All the best to you.

    Jestine Yong
    http://www.JestineYong.com

    ReplyDelete
  2. HELLO HEMFERY

    PLZ SEND ME PART LIST CONTAINING THE VALUES OF YOUR TESTER
    I AM GOING TO MAKE IT
    TNX
    BEH

    ReplyDelete
  3. Hi Behzad

    my circuit is based on the circuit on this link

    http://www.flippers.com/pdfs/k7205.pdf

    if you have any other issue please dont hesitate to ask

    Humphrey

    ReplyDelete
  4. Oh! thank you Jestine for your powerful words of Encouragements

    Regards Humphrey

    ReplyDelete
  5. thank you so much i got all info please give me your e mail address a will send you the picture of my lopt/fbt after Assembly
    rgrds
    beh

    ReplyDelete
  6. hi behzad, just clisk on my profile and click email and there you go...

    regards Humphrey

    ReplyDelete
  7. Hi Behzad

    Are you the Beh from Jestine's ERG site ?

    K7205 has been updated to Blue Ringer
    http://www.flippers.com/pdfs/BLUE_rt_assembly_manual.pdf

    Would you share the board layout after it's done ? A good prototyping board to use is RadioShack Cat#276-168. It has triple holes as well as +ve and -ve supply lines.

    ReplyDelete
  8. hello humphery

    refer to your colored diagram of above tester
    is there a dirct conection between pin 8 small ic to pin 2 big ic also pin 9 big ic with positive side of yello led also pin 7 of big ic to resistor 33k ?
    thanks for reply
    beh

    ReplyDelete
  9. hi sam
    thank you so much for your link you sent me all is useful
    thanx a lot
    beh

    ReplyDelete
  10. hi Behzad, i insist on using the template the way it is: i used it exactly the way it and got it working. so i expect you to get the same result to. pls stick on this circuit which i used otherwise you may get confused

    http://www.flippers.com/pdfs/k7205.pdf

    Also if you click on the circuit.jpg you will get a bigger version if you have not done so.

    Again thank you and all the best

    Humphrey

    ReplyDelete
  11. There is a lot of good info on this blog. thanks Humphrey Mr quick fix

    ReplyDelete
  12. Hi Foster, thank you for your encoulaging words, you are most welcome to my blog 24/7

    Kind regards

    Humphrey

    ReplyDelete
  13. can i get a circuit diagram of tester.blue ring tester and this tester both are same or what?

    ReplyDelete
  14. hi Nameless...here is the circuit link.

    http://www.flippers.com/pdfs/k7205.pdf

    this is the original version by Bob parker, blue ring tester is by ana tek..sure i would say it is one and same thing.
    Humphrey

    ReplyDelete
  15. That nice blog and i got something here

    ReplyDelete
  16. Thanks and most welcome Mobydick
    Regards Humphrey

    ReplyDelete
  17. good works, can i get ic tester

    ReplyDelete
  18. Hi Kofesto, Thanks for your compliments. which ic tester are you asking for Kofesto. there are two ic used in this circuit, I.C 1 is LM393 which is a dual comparator and I.C 2 is MC4015/CD4015/4015 which is dual 4-bit shift register.
    regards Humphrey

    ReplyDelete
  19. I just want to ask other issue which is in CRT TV.My problem with my TV is that it has a horizontal line on the screen.What would be the section affected and what particular component is defective regarding with this symptom?

    Thanks in advance Sir.
    Rombu58

    ReplyDelete
  20. Hi Rombu58: copy and paste this link on your browser for more info on this problem:

    http://humphreykimathi.blogspot.com/2011/07/gld-television-with-single-horizontal.html?utm_source=BP_recent

    Kind regards
    Humphrey

    ReplyDelete
  21. Hi humphrey, i need a flyback transformer for my LG TV. Can i used it from other company(ie. sony, samsung, phillips etc).

    ReplyDelete
  22. Hi Sang, No you can't use fbt from other models..if you can't get the spare in electronics shop near you, try to ask from technicians near you, maybe they may be having a junk lg tv and they can sell to you hopefully.

    regards Humphrey

    ReplyDelete
  23. nice share. Very useful to technicians like me. and i have already make one of this. Very useful in testing a flyback and chopper transformer

    ReplyDelete
    Replies
    1. Hi there,
      Thanks for your feedback and glad to note that you have successfully assembled one and working. congrats!
      regards Humphrey

      Delete
  24. Dear Sir,

    I finally made it today. When I give supply only one red LED lit. I further checking transformer and smps but there is no movement only one LED lit. What I have to do. How can I check circuit with oscilloscope or DMM. Kindly help me.

    Mubashir

    ReplyDelete
    Replies
    1. Hi Mubashir, That is how it should behave when all is ok, to confirm this put one probe on the main capacitor +ve pin and the other probe on the middle leg of the chopper transistor and if all is well all the led should light. regards Humphrey

      Delete
    2. Dear Sir, Good Day

      I rechecked again but symptom was same. Finally one thing which I didn't assumed that fault was in test probe. There was no connectivity. I changed it and wow all was OK. Its great gadget for my workshop. I am finding now casing for this. Thanks again.

      Mubashir

      Delete
    3. Wonderful..

      Glad to hear your success report Mubashir..

      Regards Humphrey

      Delete
  25. Hi! Humprey,
    I'm kevin from the philippines province of bukidnon. I just wanna ask a question about the project. The thing is. I've already done making the project the problem is when I turned on the set all leds lit up. I don't know what cause the problem. I'm using a transistor bc557 correct me if this part is the same with the original famous dick smith tester. Thanks humprey.

    ReplyDelete
    Replies
    1. Hi Kevin,
      This can be caused by something not done correctly..could be dry-joint, poor soldering, poor connection etc i suggest you check through the circuit slowly and carefully. this is the exact template i used and mine worked first time.


      Regards Humphrey

      Delete
  26. to mr. humphrey

    thanks for the info my friend.........ill mail you if it works for me ,by the way mr. justine wong share me about your diy esr tester that you make....i make one n my world filled with new era in electronics.thank you my friend and if you have new diy to share just mail me at nichang_graywolf@yahoo.com...god bless.....

    rey

    ReplyDelete
  27. Thank you & congrats for the great post. As Mubashir said "I finally made it today. When I give supply only first one red LED lit." ; "I rechecked again but symptom was same. Finally one thing which I didn't assumed that fault was in test probe" I checked the probes as prescribed by Mubashir. I am still facing the problem. I am simply using two plain wires as my probes. What I have to do ? Kindly help me.

    ReplyDelete
    Replies
    1. Hi Pravin...If the tester is working well this how it should...one red led is always on(serve as a power on led and if when off indicates a short...first try to short the two probes..does the led go off? that is ok..Then do alive test on a live circuit board(TV) one probe on the +ve pin of the main capacitor and the other at the main VCC pin of the control ic or middle leg of the chopper transistor...does all the led light now? care= the circuit should not have power.

      Regards Humphrey

      Delete