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CRT TV Color Problem

By on June 22, 2013

Hi Mr Yong i have a 21″ crt tv. The crt tv color problem is it shows reddish picture. A yellow colour shows orange. Whats the problem?


Check the CRT board if one of the color missing. Compare the 3 RGB transistors voltage and signals. Any differences in the transistor is the clue for you to trace the circuit. It is very obvious since the 3 color circuits have almost the same voltages and signals.

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  1. hassan ahmed

    August 26, 2013 at 1:18 am

    hi sir i have a problem with 29 inches tv lg crt the tv shows only retrace line please help me with troubleshooting tips

    • Jestine Yong

      August 26, 2013 at 9:54 am

      Hi Hassan,

      Retrace lines can be due to too high the screen voltage or bad tube. Try lower down the screen voltage by adjusting the knob at the flyback.


      • temesgen

        December 2, 2013 at 11:30 pm

        it is nice

  2. ac

    July 23, 2015 at 6:27 pm

    sir my problem for sharp crt tv no red color ..voltage reading has all the voltage on all transistor driver in the crt. greenist display..before i resolder the crt socket board,, the red comes up.. but the other day it back again to green

    • Jestine Yong

      July 24, 2015 at 8:42 pm

      HI Ac,

      Try gently knock the crt board using the back handle of the screw driver to see if there is any changes or not. If not then I guess you may have to compare the Red and Blue color circuit with the Green one. Any differences is the clue for you to troubleshoot on the comparison point.


  3. rohit verma

    August 2, 2015 at 3:26 pm

    Hi Sir
    I have 21 inches crt tv. It shows yellow picture. I have changed the transistors it worked for some times but after that it was displaying yellow again. Please help

    • Jestine Yong

      August 3, 2015 at 10:58 am

      HI Rohit,

      Compare the three RGB transistors in term of waveform and voltage. Any big differences is the clue for you to troubleshoot on that area. You may have to change the color ic and retest.


  4. vasanthkumar

    August 4, 2015 at 2:20 am

    hello sir,
    i have 21" crt tv. i have a problem that my tv screen got automatically dim to dark and there is only audio but no video,so please help sir.

    • Jestine Yong

      August 5, 2015 at 9:41 am

      Hi Vasanthkumar,

      Check to see if the heater voltage and the G2 screen voltage is present or not.


  5. jk

    August 19, 2015 at 1:20 pm

    hello sir,
    i have 21" crt tv. i have a problem that my tv screen got automatically green colour shade,if tv is on for some time it will disappeare.....but some time it will come again how it fix please help sir.

    (Problem starts when my tv was off by mcb cut off...

    • Jestine Yong

      August 20, 2015 at 10:01 am

      Hi Jk,

      I suggest that you check for dry joints at the CRT board. Probably the Green transistor and the surrounding circuitry have dry joints.


  6. Frank

    August 20, 2015 at 3:37 am

    Hello sir
    i have a problem wth a crt tv china universal board on menu Red and green colour is there but connecting to either decoder or dvd its showing black and white tried to change Av same problem tried to change Dvd player same problem and also changed the RGB its still black and please I need your help sir. Thanks in advance

    • Jestine Yong

      August 21, 2015 at 8:39 pm

      HI Frank,

      Try connect to another input jack like video in 2. What about connecting to the tuner using aerial?


  7. toshman

    October 31, 2015 at 5:19 am

    I have a sansui lcd it has a nagative picture.i tried to set it but nothing changed

    • Jestine Yong

      October 31, 2015 at 1:37 pm

      Hi Toshman,

      Negative picture you need to check on the gamma ic in the t-CON BOARD. It can be overheated.


  8. mike

    November 11, 2015 at 6:53 am

    hello Justin, i have a hisense 54cm color tv, everything is working perfect except the red color is missing, will you help me with issue please?

    • Jestine Yong

      November 11, 2015 at 10:22 am

      Hi Mike,

      Compare the Red with the green and blue circuits in term of voltage and waveform . If you see any significant differences in the voltage and waveform, you will know that you should be troubleshooting on that point or line.


  9. AK

    November 11, 2015 at 7:50 pm

    sir my CRT Tv giving wrong color after the high voltage. when I press tv/av button it show red screen. how to repair..

    • Jestine Yong

      November 12, 2015 at 7:47 pm

      Hi Ak,

      I suggest that you compare the blue and the green circuit and if you found any major different in the signal, you can start to troubleshoot on that point.


  10. Geoffrey

    November 13, 2015 at 12:31 am

    he. jestine your. articles. are very. much. practical you are my role. model in. electronicw

    • Jestine Yong

      November 13, 2015 at 10:29 am

      Hi Geoffrey,



  11. AK

    November 13, 2015 at 10:50 am

    No any diffrence there.

    • Jestine Yong

      November 13, 2015 at 11:23 am

      HI Ak,

      Can you briefly explain how did you check it?


  12. AK

    November 13, 2015 at 9:00 pm

    I have checked that RGB wired are properly connected to electon gun to to motherboard.
    If I wrong then plz explain how to do that?

    • Jestine Yong

      November 14, 2015 at 9:45 pm

      HI Ak,

      You need to use a scope to check on the RGB signal to the electron gun. Trace from the RGB IC output.


  13. niyas

    December 26, 2015 at 11:06 pm

    Hi sir,i have the problem with Panasonic 21inch CRT TV.the problem is switch ON the set is OK for some seconds after that, its goes to on,off,on,off continues screen black

    • Jestine Yong

      December 28, 2015 at 8:43 am

      HI Niyas,

      I suggest that you check for any bulged e-cap in the power supply section. Just make sure 5 volt is stable going to the supply pin of cpu ic in the tv.


  14. lhendup

    January 22, 2016 at 7:23 am

    iam very interested person to learn how to repair CRT tv repairing from you and please can you teach me both pratical way as well as theory.

    • Jestine Yong

      January 22, 2016 at 10:17 am

      Hi Ihendup,

      I suggest that you check out this link


  15. VK

    February 27, 2016 at 8:54 pm

    sir my TV,display a orange color but sound is clear so what i do to solve this problem

    • Jestine Yong

      February 29, 2016 at 3:42 pm

      Hi Vk,

      Check the color section in the crt tv board. You can compare the RGB transistor signal using oscilloscope. Any big differences in that point is a clue for you to troubleshoot on that area.


  16. Aamod Vardhan Pandey

    April 1, 2016 at 9:40 pm

    Greetings !
    I have a 15- year old Trinitron HW21M80 CRT TV which is currently
    experiencing problems.

    This Device has a problem with Picture Color. It shows many green slanting lines throughout the screen for a moment after I turn my TV on. Then it displays a light
    greenish hue over the whole screen, due to which I am being provided
    with a Worsened Picture Quality. The Objects displayed by your Sony
    CRT, in the picture, leave a sort of black shadow (I cannot
    Recognize), most probably when there's a dark background.
    This problem is increasing over time.

    • Jestine Yong

      April 2, 2016 at 3:39 pm

      Hi Aamod,

      I suggest that you check on the CRT board for dry joints especially the Green color section. If no dry joints then you may need to compare the signal between the green and the Blue/Red circuit.


      • Aamod Vardhan Pandey

        April 3, 2016 at 4:09 pm

        Dear Sir,

        How do I find out the dry circuits in the board and rectify them??


        • Jestine Yong

          April 4, 2016 at 7:58 am

          Hi Aamod,

          By your sight and by using the back handle of the screw driver to gently tap on the board. If there is changes in the color means there is dry joints or loose connection. Sometimes a bad CRT TUBE could cause such problem. Try visit this below link:


  17. Arul

    May 14, 2016 at 3:48 pm

    Have a CRT tv connect with tatasky dth. All of sudden week before, brightness rapidly changed down that could not see the images and just look dark. To add, the digital picture quality changed to cable kind quality. When asked ts, say problem with tv. Sometimes when scenes are of indoors it is so dark that could not view anything on screen.

    • Jestine Yong

      May 16, 2016 at 9:41 am

      Hi Arul,

      Try connect to other output source such as a DVD player. If the image remains dark then your tv have problem. Check the G2 voltage and make sure the voltage is between 250 to 300vdc. If the voltage is good and the OSD menu also dim then possible the pc tube is already weak.


  18. PK0909

    June 17, 2016 at 1:21 am

    Hi.. My Sony Trinitron RM-870 tv is showing greenish shade from today. It is not changing at all... what to do..please explain I have no idea about tv circuits..

  19. James malongo

    June 29, 2016 at 11:39 pm

    Hi. china gld tv cannot switch flyback hv is ok what should l check?

    • Jestine Yong

      June 30, 2016 at 8:57 pm

      Hi James,

      Can you elaborate because I don't understand your English.


  20. firas salim

    July 9, 2016 at 6:48 am

    hello sir ...
    i have problem with CRT toshiba tv which is : somtimes when i turn it on i got several horizontal green lines over the screen with green colour filter in general it continues like that for several seconds and then it back to its normal state but sometimes it does not ! yet it converts to (red) filter over the screen and stills like that !
    ps. : this problem usually happens when i turn it off and then turn it on after short time duration!

    • Jestine Yong

      July 11, 2016 at 11:29 am

      HI Firas,

      I suggest that you make sure no dry joints in the CRT board and check also for bad esr e-caps in the crt board too. If you have the scope you can compare the RGB circuit in the crt board and you will know where you should start to troubleshoot by looking at the scope result.


  21. Suresh chouhan

    July 19, 2016 at 4:54 pm

    hello sir,i have a lava 21" crt tv, in which i am facing some problem and that problem is burning blue light in the tubes crt zonel when turn on.pls help me

    • Jestine Yong

      July 20, 2016 at 7:21 am

      Hi Suresh,

      Blue light in the tube usually mean the tube has an internal leakage or the B+ supply voltage is too high.


  22. omar juma

    July 20, 2016 at 6:22 pm

    hi sir i have a problem with sony tv,21'' trinitron it displays alot'f greenish colour

    • Jestine Yong

      July 21, 2016 at 7:38 am

      Hi Omar,

      Greenish can be caused by a weak tube or bad components in the green color circuit in the crt board. It can also be caused by bad setting and corrupted eeprom ic. I suggest that you check the green color circuit board and compare with the working red and blue color circuit.


  23. Somdeep Bhattacharya

    July 22, 2016 at 3:42 am

    hello sir, I am somdeep, sir I've a 21" LG Flatron crt tv. when ever I turn on my tv set it shows blue light all over the screen and after few seconds it turns off. I called an expert to check my tv set and he says, all this things happening because of the picture tube. I don't have any knowledge regarding this. should I replace the picture tube or is there any other solution? sir please help

    • Jestine Yong

      July 26, 2016 at 7:41 am

      Hi Somdeep,

      If the signals from the CRT board to the picture are good then yes the picture tube could be at fault. It is not easy to find exact replacement for tubes.


  24. deepak saxena

    July 25, 2016 at 10:01 pm

    Sir my crt tv it shows yellow picture. I have changed the ic Tda6107ajf but after that it was displaying yellow sir

    • Jestine Yong

      July 28, 2016 at 5:39 pm

      Hi Deepak,

      You need to check the incoming and outgoing RGB Signals with Osicilloscope.