LCD TV Voltage Tolerance

Discussion in 'General Electronics Chat' started by BFreemanNH, Feb 26, 2013.

  1. BFreemanNH

    Thread Starter New Member

    Jan 6, 2013
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    0
    Working on a 2009 Samsung 55" ln52a550. The Power supply has the output voltages listed on the pins heading to the mainboard. I have 3 pins that are labeled 13V but only showing 12.38V on the meter. I have two other pins labeled 13V and they are reading 12.9V. All the 5V pins read above 5V at 5.13V or 5.17V

    My question, is 12.38V close enough to 13V for proper function?

    Will bad caps cause a voltage drop like this? They look fine but I will need to pull them to test accurately.


    The TV turns on but I have vertical lines of all sizes and colors in the center of the screen and solid colors on the right and left sides. Nothing moves or changes. The screen does not react to the remote but I am able to turn on and off the tv with it. The start-up and shutdown music plays. That's about it.

    Thanks for reading,
     
  2. MrChips

    Moderator

    Oct 2, 2009
    12,418
    3,355
    Maybe the power supply is being loaded down. See if you can find a component that gets hot.
     
  3. sheldons

    Active Member

    Oct 26, 2011
    616
    101
    post a picture of the set in the fault condition-chances are the set is scrap due to screen failure
     
  4. BFreemanNH

    Thread Starter New Member

    Jan 6, 2013
    20
    0
    Here is an image of the screen as requested.


    2013-02-24 19.06.40.jpg
     
  5. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
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    Is the ribbon cable from control board to LCD connected correctly and seated well?
     
  6. BFreemanNH

    Thread Starter New Member

    Jan 6, 2013
    20
    0
    Yes, all cables have been re-seated....twice.
     
  7. sheldons

    Active Member

    Oct 26, 2011
    616
    101
    ok that lcd screen is at fault......the connections from the tcon pcb are bonded connections via ribbon cables which are physically bonded to your lcd screen....it can be repaired but it means sending the screen to a specialist company to have the tabs rebonded on your lcd screen-but is it worth the cost involved?gone are the days of a tv set lasting some 10-15 years from new,giving excellent pictures and if you had a cathode heater short for example its an easy fix...lcds have a life of 2-3 years before failure then its throw away and buy another.....
     
  8. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    Put on eBay as "Parts Only", showing the pictures, somebody may buy it just for the power supply, or the case, or the stand, or...

    They are hard to dispose of any other way.
     
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