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About Blue Ring Tester

By on March 8, 2009

blue ring tester

Since after i sent out the March Repair Newsletter i got quite a number of response about this meter. Some already bought it and for your information this meter is not design to measure the secondary winding of Flyback transformer or even the SMPS transformer due to generally the secondary windings have less inductance.  This meter is use to check the Primary winding of Flyback transformer, Primary winding of SMPS transformer and also for any coils that have inductance of more then .3 milihenry. The higher the inductance of a winding the higher the LEDs of the Blue Ring Tester will lit. Lets put this ina neasy reference. If you see a coil with many turns then generally this meter can test it. If you see a small coil with less winding in it then expect the meter to show either one LED or no light at all.

If you can’t see the winding, you can always compare with another good equipment coil and see the result. If you can’t see the winding and do not have any equipment for comparison then you have to use inductance meter to check for the value and make sure it has more than .3 milihenry.

If you do not have inductance meter then i guess you just have to roughly guess the inductance (by looking at the physical size of the coil) and expect some result. If the LED is fully lit you are now sure the coil has no shorted turns.  If the coil had caused the meter LED to goes off then suspect it may have a severe shorted turn but again  it still come back to your experience whether wants to replace it or not.



  1. john preher

    June 3, 2009 at 1:10 pm

    Hello Jestine,

    Thought I would share how much time this tool save me today.I had a 32" TV with chirping SMPS transformer when you try to turn on, no HV(High Voltage), only chirping continuously.Because of working with this TV model before I suspect problem in Horizontal circuit.Using your technique I first use ring tester on flyback primary winding and it checks shorted,next step I desolder pins to primary winding and make sure they are nicely cleaned and "floating"(not touching sides of hole in trace pad), checking primary winding of FBT again desoldered from board lights up all light of ring tester, flyback is good so I know I have shorted component now in the horizontal circuit.First thing I suspect is the H.O.T.(horizontal output transistor) I remove and check, it is shorted between all pins.I checked all other components in the Horizontal circuit including damper diode safety capacitor etc....but found know other faults ,however close inspection of the PCB let me see that the horizontal drive transformer had developed bad ring cracks.soldered the ring cracks, put all the components back in place, except for the H.O.T. which I brought to my shop to order replacement, which I am confident will fix the TV, the point of this story is the trouble shooting time was only 10-15 minutes, thanks to having the right tools for the job like the blue ring tester.

  2. admin

    June 3, 2009 at 5:44 pm

    Hi John,

    Yes have made the right decision of having this tester-it had help me in so many repair and very grateful for the designer.


  3. Cedric Sandiford

    December 10, 2009 at 12:18 am

    Hi Jestine,
    Iam living in the country of Barbados and i saw on the site The Blue Ring Tester. I was wondering where i can purchase one. What would be the overall price. For shipping and handling to my country(Barbados). Do the store take money orders, and approximately how long would it take to reach me. I know that Christmas is around the corner and things would be hectic. I appreciate all you have done in the past months for those newsletters. They came in very handy and once again i thank you and wish you and your family all the best for 2010 and looking forward to a great year.


  4. admin

    December 10, 2009 at 2:36 pm

    Hi Cedric,

    I've already sent a personal email to you.



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