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TV/Monitor Fault Diagnosis

By on September 30, 2010

tv fault

This great website was recommended by Lee Davey and please click on the photo to visit the website for more information.



  1. beh

    September 30, 2010 at 12:53 pm

    thanks jestine
    thanks lee
    is a good refresher article

    • Enoch

      November 4, 2020 at 3:09 pm

      Good morning sir I have CRT TV 74cm standby flickering please help

  2. henry Elcock

    December 8, 2010 at 9:18 am

    Dear Sir Iam an electronc Repairerihave a television that is spiting the high voltagae at the side of the flyback cap i tried another tube but the same thing is happening i suspect that the high voltage is to high what is the cause of that.Please assist.thank you.

  3. admin

    December 8, 2010 at 10:26 am

    Hi Henry,

    Are you referring to arcing? If yes then the flyback have problem.


  4. Masese

    December 10, 2010 at 11:37 am

    where is the B+ locacted on the main board?. how can i tell this is the B+ circuit?. Please advice.

  5. admin

    December 11, 2010 at 11:54 am


    For monitor, you will see a B+ fet, B+ coil and a diode and capacitor but for tv you could only trace the line from smps output to one of the pin in the flyback transformer. This voltage is usually 110 vdc.



    January 18, 2011 at 6:50 am

    My picture tube displays less color(faded).is there anything ican do about it?what about rejuvenating the picture tube?how?please.

  7. admin

    January 18, 2011 at 9:14 am

    HI Ali,

    Please visit this link:



    January 26, 2011 at 6:08 am

    good evening,sir.i have a SAMSUNG TV with a defect of no picture but power LED is on.i also observed arcing at g2 terminal located at neck board causing its picture to distort until it's gone.horizontal transistor is okay when i checked it.what could be the culprit?

  9. admin

    January 26, 2011 at 6:21 am

    HI Ali,

    G2 arcing could be due to bad tube and the anode voltage is too high. Make sure the B+ voltage is within the spec.


  10. Amir Mukhtar

    March 13, 2011 at 5:21 am

    Nice Fault diagnostics website.
    Thanks you Sir jestine and Mr. Lee Davey for good sharing information.
    i have seen website and found great information regarding problems and its solution's guidance with picture images.

    Thanks you
    Amir mukhtar

  11. Ramsey Fernando

    March 24, 2011 at 3:51 am

    dear sir,
    I'm workig as electonics field and I'm very intersting to know
    correct step of fault diognocis of T.V from A to Z,So please
    send tutorial includig with diagram to my E-Mail address.

    I request your Help

    Thank you Sir


    W.R.P Fernando

  12. admin

    March 24, 2011 at 9:19 am

    HI Ramsey,

    Sorry i do not have such info. I suggest that you get the info from below:


  13. chandrashekar

    September 13, 2011 at 6:31 am


    In compaq MV7540 moniter -Self Rastar OK but after connecting the moniter to CPU the Moniter LED going to AMber color and no Picture

  14. admin

    September 14, 2011 at 7:13 am

    HI Chandrasekar,

    It can be the monitor CPU or the eeprom ic have problem. Make sure also the vga cale internal wire especially the vertical and horizontal is not broken.


  15. Ntsikelelo ivan james

    September 20, 2011 at 8:26 am

    How to take the voltages on television and what voltages should you have on power supply,second power supply and other stages, where to get the tv manuals?

  16. admin

    September 21, 2011 at 9:42 am

    HI James,

    I suggest that you get a book on TV repair (like the one from by Homer L Davidson "Troubleshooting and repairing solid state TVs) because it has full explanation about voltages on various circuit. As for tv manuals you can click on this link below:

  17. endalemaw

    October 17, 2011 at 9:06 pm

    hello dear justin haw are u? I am writing u this from ethiopia, i have this panasonic tv .it works fine for 20-30 minutes and then on the screen it flashes frequently. And after i off it it will also works the same time and flashes again. I trayd all the best i can and i was also adviced with someny technsians but i get nothn. What is ur advice?

  18. admin

    October 18, 2011 at 3:28 am

    HI Endalemaw,

    When it flashes, does all the voltages at the CRT remain stable or fluctuates?


  19. Ahmad Nasir Mohamad

    December 31, 2011 at 11:05 am

    I would be glad if you could set up a club for tv repairers so that we can share our problems and get help from participating members. So far I do not come across such a club in Malaysia.

    Thank you.
    Ahmad Nasir/0105228699.

  20. admin

    December 31, 2011 at 12:34 pm

    Hi Ahmad,

    Thanks for the suggestion. In order to set up this kind of club needs lot of time and resources and i guess at this current moment I'm not ready for it.


  21. Nkwenti

    January 13, 2012 at 6:25 pm

    Dear sir.
    please i need your help to repair my TV set, the TV is color Chinese made...mark sharp, the TV Micro processor is LA 76810,
    it comes on and when is search for channels, it cant work, but the tuning voltage is very stable with across the tuner, as for the other Tv set having the same Micro Processor, it only gives and receive TV signals but no Video signal can work with it, Dear sir.
    your help will kindly be email address is (

  22. admin

    January 15, 2012 at 3:07 pm

    Hi Nkwenti,

    Is both tv can run on dvd player? I mean if there is any display on the av mode?


  23. Elvin

    February 8, 2012 at 12:23 pm


    I'am new in repairing monitor and tv.I only know a little bit..I have monitor HP s5500 that cannot be switch on...before that the monitor relay start to clicking on and off and turn ok after i shut down and on the monitor suddently shut off with high contrast and noting on the screen.the power led won't lit anymore..i check the big capasitor it have 320v.can u tell me what the next step i need to check on the power me if possible.thnx in advanced.

  24. admin

    February 9, 2012 at 12:52 pm

    HI Elvin,

    Does the monitor now have good output voltages from the power supply?


  25. ntsikelelo ivan james

    March 17, 2012 at 2:52 pm

    my tv has lost colour to rainbow colour i changed the ptc but still the same. this thing happened after i changed the screen coil please help

    • Jestine Yong

      March 18, 2012 at 6:40 am

      HI Ivan,

      If you use a demagnetizer and still can't remove the color purity problem then the pc tube already have problem


  26. ntsikelelo ivan james

    March 19, 2012 at 5:40 am

    HI sIR
    I want to buy and resell the tv components especial power supply parts, is there any good factry where i can buy the components very cheap? I am the south african person people need the components and i want to order them.

    • Jestine Yong

      March 20, 2012 at 8:43 am

      HI Ntsikelelo,



  27. Zitha Nyanisa

    March 20, 2012 at 9:05 am

    Hi i've problem with my logik 74cm colour TV modle no:-2974 is blowing line drive transister after a few minute how to solve it?

    • Jestine Yong

      March 20, 2012 at 7:31 pm

      HI Zitha,

      Please check on this link:


  28. Ntsikelelo ivan james

    March 20, 2012 at 11:31 am

    Hellow sir please quote me the following parts:-) d 2498, d2499, c 3807, c 2655, la 78040, cv 203, in 4148, in 4007, C 817 coopler, bu 508, cap 100 uf 400v, 5watt 4.7 ohm resistor, A 1015, C 1815 , k 24C08

    • Jestine Yong

      March 20, 2012 at 7:30 pm

      HI Ntsikelelo,

      Sorry I do not sell parts. You need to order from


  29. victor

    March 23, 2012 at 7:58 pm

    great work

  30. Annemarie

    April 11, 2012 at 2:05 pm

    Good day.
    I have a Logic 80cm tv. It was working fine this morning but when I turned it on this evening, NO POWER. What could be the problem?
    Thank you.

    • Jestine Yong

      April 12, 2012 at 8:47 am

      HI Annemarie,

      It can be loosen ac power cord, blown fuse, shorted components and many other factors. If the fuse and the ac cord all check to be good then you may need to perform the voltage test on the power supply. Make sure the smps output have output voltages if no then check all the components in the primary side.


  31. Gerson

    September 10, 2012 at 9:34 am

    Hi Sir
    Hi I've problem comes from anode cap its noise and smell ozone then the display of picture is horizontaly dis-aline, what was the problem of my CRT-TV?
    Thank you....

    • Jestine Yong

      September 10, 2012 at 8:22 pm

      Hi Gerson,

      Check the supply voltage to the vertical output ic first. Make sure no dry joints. If all tested good then directly replace the vertical output ic. As for the ozone smell amke sure the anode cap area is clean.


  32. Amir Mukhtar

    June 10, 2013 at 4:03 am

    Thanks you again for Great addition.

    thank you
    Amir Mukhtar

  33. raymundo saura

    October 6, 2013 at 10:01 am

    even on the reply\question of everybody i do got some very important info and helpful on my part thanks for the every article you publish GOD bless

    • praveen

      July 17, 2016 at 10:39 pm

      Hi .i am praveen.i have new tv kit using in akai 21 inch tv. The picture tube back blow but no display. In cpt 180 volt in rgb other voltage. H transistor okipls give solution. .

  34. Dejen

    February 17, 2016 at 3:36 pm

    hi sir
    i am from Ethiopia, i live in remote area, my tv power supply bord burn ic D2498. i have ic D2499,may i replace it. b/c D2498 is not available.

    • Jestine Yong

      February 18, 2016 at 7:22 am

      Hi Dejen,

      You are referring to transistor or IC?


  35. Samuel

    March 26, 2016 at 12:19 pm

    Am a tech frm kenya i have a two sets of LG flat ron tv display on screen signal sound is their,shooting 110 in flyback ok,180v on tube base hearter are not on,whats the problem sir.

    2.display on screen very distorted &shows light @ top left other parts of screen dark

    • Jestine Yong

      March 28, 2016 at 5:05 pm

      HI Samuel,
      If the tube base is not On this means the flyback is not energized. Have you checked if the base of HOT have any pulse waveform?
      Second case you need to send the photos to my email.


  36. ganiyu

    August 16, 2017 at 6:13 pm

    hello my tube tv is not receiving tv channel and the av only supply sound no picture what should i do


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