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Tv lg chassis sc-023a high voltage in + b

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Hello friends, I hope you have a warm greeting from Venezuela ...
I have this tv which the m
+ b is 115v and I have 170v
the client told me that at times
when he plugged it in he left it like that and turned it on the next day ..
Already discarding the high + b I focused once on the part of the source and replace the 2 filters of + b replace the se110. Also the optocoupler. The current here is 110v.
which measured the main filter and I think it has a super high voltage of 200v. I do not know if it is normal but the TV that always fixed the main filter reaches 150 or 160v. I also replaced that filter but the fault persists .. thanks in advance


3 Proposed Solutions

Diagram here ::

https://diagramasde.com/blog/25156/lg_chassis-sc-023a-rp-21fa37a-pdf-LG-GOLDSTAR-lg_chassis-sc-023a-rp-21fa37a.html


Until stabilization B unlink the source of its real load FBT and TSH.
Place a filament bulb of a power equal to or less than the power of the TV as a temporary source load.

In this way, make the relevant revisions and change until the voltage of + B is stabilized at its nominal value.
  • 4 days ago

    Avatar de Gomez4G

    Good morning friend thanks for answering thanks for the diagram ... I already have everything unlinked until the yoke disconnects.

    Friend another question when I plug the TV I have 112v
    I change the scale of the tester to continuous current measured after the t802 coil 2 voltages both of 95v and dentran leave at d8813 and at the exit that goes to the main filter there are already 210v. Also change
    The d8813 is an integrated 4-legged .. but I still have that high voltage. Tell me 210v on the main filter is normal ...
    The other is the bridge rectifier could also be damaged.

  • 4 days ago

    Avatar de Javier Chavez C

    What AC voltage governs in your locality.

    The tensions in the primary stage are measured with reference hot ground (HOT).
    And in the secondary stage with the reference of cold earth (COLD)

    Both in direct current range

  • 4 days ago

    Avatar de Gomez4G

    Yes, of course, I am measuring it right on its positive and negative pins on a direct current scale since that is the hot or hot part .. for the measurements in the secondary mass of the screen .. the current in my location is of 110v
    According to a class I saw
    The voltage can be multiplied for example
    (110v x 1.41 = the result is 155.1v) and if it is current (220V x 1.41 = the result is 310.2v) that is true or false

  • 4 days ago

    Avatar de Javier Chavez C

    Yes.

  • 4 days ago

    Avatar de Gomez4G

    Ok my thanks for the moment I'll be warning progress

  • 4 days ago

    Avatar de Javier Chavez C

    If you have solved the problem, it is now up to you to close the issue by assessing as SOLUTION the proposal that influenced your determinations.

Hello Friend. First check all the elements that are in the source, change the small filters and the opto coupler, then check the resistance diodes, and filters that are after the choper .--- and desolda the pin of the + b. of the flayback and give it power to open if the stamby LED goes out if it turns off then it may be that the flayback, has short internal tests with another flay, that is of the same number or a good replacement. and check the tsh. Cheers
  • 4 days ago

    Avatar de Gomez4G

    Good friends I already have the + b controlled in 89v in standby. But the q16 is still protected because this brings that unique ocp protection I put a focus of 200w on cerie a + b but the same does not turn on when giving on makes turn on but remains in standby. Checking the supply voltage of the microjungla. In pin 17 hvcc I am not getting the voltage since this should have at least 5v at the time of giving power through the ic804 but when I give power only 00.6 appears and it remains at 0v again

  • 4 days ago

    Avatar de manolo karvalo

    friend. place the q16. and do the test of desoldering the pin of + b. of the flayback, and press the power button to open if the stamby led. turns off.

  • 4 days ago

    Avatar de Gomez4G

    Nothing does not turn off. Apparently I still have a problem at the source .. put a 100w focus on the + by filter and the bulb is blinking. I don't know if it's because the light bulb is 100w. But I think I shouldn't flick through the main filter and now there is only 110v in the 150v spot

  • 4 days ago

    Avatar de manolo karvalo

    friend. Check that main filter may be undervalued, there should be 160volt. in ac.

  • 4 days ago

    Avatar de Gomez4G

    If friend already change it it turns out that it is not the source that is bad .. apparently my tester was damaged .. I already changed the battery .. and I also tried another TV and it measures me 110v I will buy one I will warn you have it

  • 4 days ago

    Avatar de Gomez4G

    Friends sorry for the delay is that the Christmas thing was strong. I already bought another multimeter. And the fault was resolved by a devalued filter .. c850. What goes along with the ic804

SOLUTION ACCEPTED
Friends sorry for the delay is that the Christmas thing was strong. I already bought another multimeter. And the fault was resolved by a devalued filter .. c850. What goes along with the ic804