Repairing Toshiba 29″ 2927DE CRT Television

By on April 17, 2008



This Toshiba 29″ 2927DE 29″ CRT TV was collected from a friend’s house. The complain of this TV was no signal-only the blue raster and no sound even with the TV’s antenna connected. For your information i don’t repair television but i do analyze Television circuit, and read TV troubleshooting magazine and book especially the TV Repair book by Homer L Davidson. Since this TV is belong to my friend so I’m doing a favor for my friend to repair the set.

toshiba tv

If a TV set have raster, no picture and no sound chances are high the tuner, IF section or the AGC circuit have problem. Since TV tuner is the easiest to see i started off with the tuner first. As usual in any electronic repair, i would use the handle of my screw driver to knock on the suspected section which is the tuner. Surprisingly i got back the picture and sound the moment i hit the tuner casing. Turning back to see the circuit board, i found a slight dry joint in one of the tuner pins. After resoldering it i thought it would be fine and after hitting the tuner again the same problem arise again. I concluded that it was the tuner internal section that might have dry joints.

I soldered the tuner out again removed both metal covers and began to see with the help of magnifying glass. Ha! got it, found two pins that had very obvious dry joints. After applying fresh solder on all of the internal joints, the bright, nice picture and sound came back again. I just love electronic repair!

toshiba tv repair

 toshiba tv

 toshiba television tuner

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217 Comments

  1. yanyoo

    May 22, 2012 at 3:45 am

    hi sir justine i had a tv LG wen i replace the flyback the tv ok but after one week it back again the power led is blenking 

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    • Jestine Yong

      May 27, 2012 at 4:07 am

      HI Yanyoo,

      Back again? Do you mean the flyback spoil again?

      Jestine

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  2. yanyoo

    June 14, 2012 at 1:49 am

    no just her case before blinking her power led but the flyback looking gud

    Likes(0)Dislikes(0)
    • Jestine Yong

      June 15, 2012 at 8:48 am

      Hi Yanyoo,

      Try use the below link to isolate the problem:

      http://www.scribd.com/doc/2957819/TT204-Identifying-television-SMPS-problems

      Jestine

      Likes(0)Dislikes(0)
  3. cedrick

    June 26, 2012 at 6:56 am

    sir my samsung tv has white lines and grey background all over the screen whats seems to be the problem????/

    Likes(0)Dislikes(0)
    • Jestine Yong

      June 26, 2012 at 8:02 am

      Hi Cedrick,
      Check if the G2 voltage is too high or if the G1 voltage is zero volt. It should not be zero volt.

      Jestine

      Likes(0)Dislikes(0)
  4. yanyoo

    July 19, 2012 at 7:52 am

    hello sir i have a amlifier sakura the resistor easily burn 220 ohms have power but no sound wat should be the cause?thxz

    Likes(0)Dislikes(0)
    • Jestine Yong

      July 19, 2012 at 8:36 am

      Hi Yanyoo,

      Check along the burnt resistor line to see if there is any other component bad. Resistor rarely burn by itself unless if there is something shorted.

      Jestine

      Likes(0)Dislikes(0)
  5. yanyoo

    July 19, 2012 at 8:11 pm

    thank you sir
     

    Likes(0)Dislikes(0)
  6. yanyoo

    July 25, 2012 at 2:16 am

    hi sir i had a jvc component dvd 5 disc theunit  is on but sumthing went wrong the system going crazy the botton ol not function 
     

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    • Jestine Yong

      July 25, 2012 at 6:46 am

      Hi Yanyoo,

      Have you check if all the output voltages from the power supply are good and stable?

      Jestine

      Likes(0)Dislikes(0)
  7. yanyoo

    July 27, 2012 at 7:46 am

    sir halow im olwz read ur blog im electronics student how can i get a book from u?

    Likes(0)Dislikes(0)
    • Jestine Yong

      July 27, 2012 at 10:10 pm

      Hi Yanyoo,

      I have sent an email to you. Please check your inbox.

      Thanks.

      Jestine

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  8. yanyoo

    July 27, 2012 at 7:55 am

    helow sir i had lcd monitor the dsplay had distrupting color up and down horizontaly i cant see the dsplay properly

    Likes(0)Dislikes(0)
    • Jestine Yong

      July 27, 2012 at 10:08 pm

      Hi Yanyoo,

      Is all the output voltages from the power supply good?

      Jestine

      Likes(0)Dislikes(0)
  9. yanyoo

    July 28, 2012 at 12:15 am

    the lcd monitor was wet after typhoon sendong her n philpns it cud b the cause?

    Likes(0)Dislikes(0)
    • Jestine Yong

      July 28, 2012 at 8:36 pm

      Hi Yanyoo,

      Yes this could be the cause. Make sure inside is dry up using hair dryer and start checking on the components.

      Jestine

      Likes(0)Dislikes(0)
  10. yanyoo

    August 26, 2012 at 12:06 am

    hi sir justin i had a sakura amplifier av-5023 have power but no sound only the sorround speakr having sound,the fuse after the positive terminal of filter capacitor blown....the audio ic is good pls help me to solve this problem....more power..

    Likes(0)Dislikes(0)
    • Jestine Yong

      August 27, 2012 at 10:38 pm

      Hi Yanyoo,

      If the fuse blown that you need to check on the component especially semiconductor for short circuit.

      Jestine

      Likes(0)Dislikes(0)
  11. yanyoo

    August 26, 2012 at 12:53 am

    sir justin the two capacitor stalled in board positive-negative-positive-negative is this correct 

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    • Jestine Yong

      August 27, 2012 at 10:40 pm

      Hi Yanyoo,

      if the primary section is using the two main filter caps then yes it is correct.

      Jestine

      Likes(0)Dislikes(0)
  12. Liz

    September 20, 2012 at 7:11 am

    Hi Jestline
    I am looking for someone to help me repair an old CRT tv (I guess more than 10 years easily).  While watching tv, the screen was blackout but we can still hear the audio. Few seconds later, we heard a small explosion inside the TV, audio gone and burnt smell everywhere.  Do you possibly know what is wrong and whether this can be repaired?
    Thank you.
     

    Likes(0)Dislikes(0)
    • Jestine Yong

      September 20, 2012 at 8:05 pm

      Hi LIZ,

      It could be flyback transformer problem or the main filter cap already exploded. I suggest that you send to any nearby electronics repair shop for them to check it out.

      Jestine

      Likes(0)Dislikes(0)
  13. Liz

    September 20, 2012 at 11:03 pm

    Thanks for your reply.  If it is really the problems you mentioned, is it repairable?

    Likes(0)Dislikes(0)
    • Jestine Yong

      September 21, 2012 at 12:12 am

      Hi Liz,

      It is repairable if there is no components burnt beyond recognition. This means the repairer have to open and check it first.

      Jestine

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  14. Liz

    September 24, 2012 at 2:39 am

    Okay, I will send it to a shop then.  Thank you, Jestine

    Likes(0)Dislikes(0)
  15. nasrul

    November 26, 2012 at 11:03 pm

    hi bos...
    my crt (panasonis 29") problem like the picture is moving (shrinkage and expand all time) than yesterday cannot on... blinking led (red to green to red........) what the problem?
    thanks...

    Likes(0)Dislikes(0)
    • Jestine Yong

      November 27, 2012 at 6:32 am

      Hi Nasrul,
      Is the output voltages from the power supply good and stable?

      Jestine

      Likes(0)Dislikes(0)
  16. nasrul

    November 29, 2012 at 9:17 pm

    hi...
    tv can on now (just luck after i try to trobleshoot it) but the picture remain moving.. is it about power?
    thanks

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    • Jestine Yong

      December 3, 2012 at 11:21 pm

      Hi nasrul,

      If the power supply output voltages are good and the display still moving then you may need to check on the jungle chip area. Moving can be cause by vertical/horizontal section.

      Jestine

      Likes(0)Dislikes(0)
  17. Eric Lam

    December 23, 2012 at 10:10 am

    Hi,
    My Toshiba Bomba 20" TV couldn't turn on and only can see a red dot LED when power on, where was gone wrong?
     
    Thank you.

    Regards,
    Eric Lam

    Likes(0)Dislikes(0)
    • Jestine Yong

      December 25, 2012 at 6:47 am

      HI Eric,

      It could be the fault of TV CPU or eeprom ic. Make sure the both IC are getting the right supply voltage.

      Jestine

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  18. yanyoo

    January 3, 2013 at 10:10 pm

    hi! sir justin, its me again, i had a CRT tv ahm! standby mode only but the B+ supply is ok. could you help this problem... thank you sir and god bless!!!

    Likes(0)Dislikes(0)
    • Jestine Yong

      January 4, 2013 at 8:53 pm

      Hi Yanyoo,

      Standby in crt could be caused by bad tv cpu, eeprom data corrupted and improper supply voltage
      Jestine

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  19. yanyoo

    January 11, 2013 at 7:25 pm

    HOW CAN I REPAIR THIS PROBLEM SIR

    Likes(0)Dislikes(0)
    • Jestine Yong

      January 12, 2013 at 12:37 am

      Hi Yanyoo,

      You just have to test the supply voltage and if it is good then replace the cpu or the eeprom ic.

      Jestine

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      • yanyoo

        October 29, 2013 at 12:18 pm

        hi sir i had a tv sharp 21 inchs the picture so blurd even i adjust the focus and screen of flyback nothing happens,its still blurrd what should i do?

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        • Jestine Yong

          October 29, 2013 at 12:51 pm

          HI Yanyoo,
          If it still blur then the picture tube could have problem. Sometimes the flyaback itself also have problem because it can't produce the 5 to 10kvdc that is required by the tube.

          Jestine

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          • yanyoo

            October 31, 2013 at 7:26 am

            thnk you sir

            Likes(0)Dislikes(0)
  20. yanyoo

    December 13, 2013 at 10:19 am

    hello sir jestine i had a crt tv wen i turn on the tv only red light appear standby mode only,,,, the b+ supply ok but the G2 Into the crt board have no supply voltage,,it could be the flyback defect sir?

    Likes(0)Dislikes(0)
    • Jestine Yong

      December 14, 2013 at 5:59 pm

      Hi Yanyoo,
      Standby means either:

      1) CPU IC got 5 volt but cannot send out the "On" signal due to the ic itself have problem or the EEPROM IC have corrupted

      2) CPU IC could send out "On" signal but it can reach the main power supply section due to bad components in the optoisolator ic and surrounding components problem

      3) On signal can reach the main power supply but main power supply it self have bad components like shorted secondary diodes, bad power ic and etc.

      Jestine

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  21. yanyoo

    December 28, 2013 at 11:31 pm

    hello sir id lost the component of my tv along wth the tuner small round metal plate with 3 legs,,i cant fix my tv no signal...KONKA 19 INCH..

    Likes(0)Dislikes(0)
    • Jestine Yong

      December 30, 2013 at 11:01 am

      HI Yanyoo,

      You need the find the right schematic because I do not have the info for this.

      Jetsine

      Likes(0)Dislikes(0)
  22. yanyoo

    February 2, 2014 at 9:43 am

    hi sir the resistor 10w2RK has open could i use a jumper wire as a relplacement of this component.....

    Likes(0)Dislikes(0)
    • Jestine Yong

      February 3, 2014 at 11:24 am

      HI Yanyoo,

      No, you have to use back the same value.

      Jestine

      Likes(0)Dislikes(0)
  23. yanyoo

    February 2, 2014 at 9:45 am

    hello sir i had a tv cant reach any channel the supply to the tuner is stable ive replace a tuner but nothing happen sir..what im gonna suppose to do

    Likes(0)Dislikes(0)
    • Jestine Yong

      February 3, 2014 at 11:30 am

      HI Yanyoo,

      If other input could work like running on a dvd player then you may need to get the schematic to troubleshoot the fault since you have mentioned that you have checked the supply voltage and replaced the tuner.

      Jestine

      Likes(0)Dislikes(0)
  24. yanyoo

    February 22, 2014 at 7:54 pm

    sir can i have a favor pls help me to become your student to met you in personal

    Likes(0)Dislikes(0)
    • Jestine Yong

      February 22, 2014 at 9:22 pm

      I suggest that you get Humphrey's ebook from the link below as he could guide you to become good in CRT TV Repair. We need to invest in order to make our life better:

      http://www.electronicrepairguide.com/crt-tv-repair-ebook.html

      Jestine

      Likes(0)Dislikes(0)
  25. Terrence

    April 28, 2014 at 6:57 am

    Hi Jestine,

    I got a samsung crt tv which has got 320v dc present on the main boosting cap, this voltage also present on the ic collector pin. But there is no voltage on other pins. totally zero.

    I check the 2.2 ohm K bleeder resistor but got 0.7 ohm. What you suggest bro.

    TL

    Likes(0)Dislikes(0)
    • Jestine Yong

      April 28, 2014 at 11:52 am

      Hi terrence,

      I suggest that you check all the components in the primary side. If all checked to be good then direct replace the power ic and retest. Make sure no shorted diodes in the secondary side.

      Jestine

      Likes(0)Dislikes(0)
  26. yanyoo

    June 11, 2014 at 4:44 am

    hello sir i had a sharp tv when i turn on the tv, the b+ shutdown rapidly

    Likes(0)Dislikes(0)
    • Jestine Yong

      June 13, 2014 at 12:02 pm

      Hi Yanyoo,

      What is the B+ supply voltage? How high it goes before shutdown? What about other output dc voltages from the power supply are they high too?

      Jestine

      Likes(0)Dislikes(0)
  27. yanyoo

    June 11, 2014 at 4:47 am

    sir i had also a tv unit no display, audio only but after 10 seconds the unit off itself

    Likes(0)Dislikes(0)
    • Jestine Yong

      June 13, 2014 at 12:01 pm

      Have you checked if the power supply output voltages good or not? What about the B+ supply voltage to the flyback?

      Jestine

      Likes(0)Dislikes(0)
  28. yanyoo

    June 15, 2014 at 10:50 pm

    the b+ supply is 125v no its stable before shutdown,

    Likes(0)Dislikes(0)
    • Jestine Yong

      June 16, 2014 at 10:34 am

      Hi Yanyoo,
      125 volts seems to be too high. What are the other output voltages from the power supply?

      Jestine

      Likes(0)Dislikes(0)
  29. yanyoo

    August 19, 2014 at 4:52 pm

    sir i had a tv sharp model 21V-FK200M the unit will auto shutdown i olredy resolder all the dry joints isnt the flyback?or the system?

    Likes(0)Dislikes(0)
    • Jestine Yong

      August 20, 2014 at 8:08 pm

      it can be the flyback or the system or even high voltage circuit. Make sure the B+ voltage is within range.

      Jestine

      Likes(0)Dislikes(0)

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