Please LG TV no picture but sound slight buzzing

[Fixing222]

Re: Please LG TV no picture but sound slight buzzing

BTW, I also expect the backlighst to come on (if all the Voltages and Control signals are present on the power supply board) when both ribbon cables between T-CON and the panel are not connected, so that may be another issue beside bad VGH Voltage.

EDIT: Did it you were right taped of part of the right ribbon cable and get 27v but the back light on and off isn't good. Maybe ill leave it for a while.

Cheers for all your help i learned from it and the tests were fun felt like i was a pro aha. Like i said really appreciated always wanted to do the tests i see on youtube and inspired me to learn more, thanks.

[Fixing222]

Re: Please LG TV no picture but sound slight buzzing

BTW, I also expect the backlighst to come on (if all the Voltages and Control signals are present on the power supply board) when both ribbon cables between T-CON and the panel are not connected, so that may be another issue beside bad VGH Voltage.

May I ask while I'm learning if these voltages are correct as the mini diagram shows different thank you
From left of the picture 210-220v, 140-50, 140-150, 55-70 (42 inch TV)

[Diah]

Re: Please LG TV no picture but sound slight buzzing

let try from start.. be sure do exact the following with out any try from your self please..

1- put back your Original T-CON
2- disconnect the LCD totally from T-CON and never connected it again until finish our test and repair.
-----------------------------------

Now upload photo on your PWB socket with it connected to Main Board.. while the TV ON check voltage and write down all voltage measurement you have..

also report if LED back light flashes or stable on.. you can see them also from back side..

[Fixing222]

Re: Please LG TV no picture but sound slight buzzing

let try from start.. be sure do exact the following with out any try from your self please..

1- put back your Original T-CON
2- disconnect the LCD totally from T-CON and never connected it again until finish our test and repair.
-----------------------------------

Now upload photo on your PWB socket with it connected to Main Board.. while the TV ON check voltage and write down all voltage measurement you have..

also report if LED back light flashes or stable on.. you can see them also from back side..

The reading is from the bottom (ground) 0 12, 12, 0, 23, 0, 3, 3, 3
On the led part from left to right of pic 50-60v 140-150v, 140-150v, 210-220v
All seem healthy voltages why is the led different on the far left and right?

[Diah]

Re: Please LG TV no picture but sound slight buzzing

you do wrong measurement on LED back light socket, you have 2 group black - and white +. so you should read with DM - + direct on black and white of each group each group--- just black - and white + and compare the value as written on printed label 157.V as your set 43

[Fixing222]

Re: Please LG TV no picture but sound slight buzzing

you do wrong measurement on LED back light socket, you have 2 group black - and white +. so you should read with DM - + direct on black and white of each group each group--- just black - and white + and compare the value as written on printed label 157.V as your set 43

Thank you i can finally rest while i was testing i put ground of multi meter to chassis the positive to the white middle wire alas i see the backlight stays on while like this..


So i got someone to hold the tv while i did this and saw a small ink part in corner of T.V strange but know what was wrong now anyway

For the future is this what you mean as i got under 1v when i tried

[Diah]

Re: Please LG TV no picture but sound slight buzzing

So i got someone to hold the tv while i did this and saw a small ink part in corner of T.V strange but know what was wrong now anyway]

you need now to disassemble the LCD panel out of the set.

ready clean & safe place to store the panel, be sure when you disassemble the defuser sheet plate behind the panel to mark the order of them and which side are on top.

check with visual eyes your LED back light. remember LG always can work with out Panel connected.

check with tourch lighting the LCD from back side to inspect the INK point you mentioned.
post photo on the LCD TAP plate of both side.

[Fixing222]

Re: Please LG TV no picture but sound slight buzzing

you need now to disassemble the LCD panel out of the set.

ready clean & safe place to store the panel, be sure when you disassemble the defuser sheet plate behind the panel to mark the order of them and which side are on top.

check with visual eyes your LED back light. remember LG always can work with out Panel connected.

check with tourch lighting the LCD from back side to inspect the INK point you mentioned.
post photo on the LCD TAP plate of both side.

Hi thanks it wasn't as daunting as it seems the taking of the panel.

my findings front of LCD is fine then I looked at back.like you said and saw crack.

Then when I looked at led back strips I had to film on phone as they flash on and off so fast and every 5 or so seconds.

I found one led wasn't lighting up at the very bottom right corner.

To my final test when I hookup my multimeter to ground and stick a probe to the white wire running from powerboard to LEDs all backlights light up solid except the top row which flashes intermittently and the bottom row which flashes intermittently except one led at the right end of the panel which doesn't come on at all.

Thanks to all who helped as I gained good experience from this

[Diah]

Re: Please LG TV no picture but sound slight buzzing

sorry to hear that.. its awful. but did this crack on screen ? to me via photo look a scratch
.. if its scratch worth to repair LED of course