LG 42LK450 no sound or hdmi

[budm]

Re: LG 42LK450 no sound or hdmi

If it does not change state when it is grounded or when 3.3V is applied, then I do not why it does not change. I will have to try that on other panel to see if it will do anything. I have no idea right now.

[tibimakai]

Re: LG 42LK450 no sound or hdmi

What I'm saying, that maybe it is grounded from the factory and it's no point for me to apply 3.3V to that point.

[budm]

Re: LG 42LK450 no sound or hdmi

If it is grounded from the factory, then the resistance reading between pin 6 and ground should show <1 Ohm then.

[tibimakai]

Re: LG 42LK450 no sound or hdmi

I have just measured it and it's 0.764KOhm.

[tibimakai]

Re: LG 42LK450 no sound or hdmi

I have removed the resistor, thinking that maybe it wasn't touching only pin #6 and tried with a needle and I have seen some kind of flipping of the screen, basically something was going on at the center of the screen. The flipped menu items were on both sides of the screen, course one side it was flipped.
I will give it another go at it, tomorrow.

[tibimakai]

Re: LG 42LK450 no sound or hdmi

Bud, you think that this switch(0V to 3.3V) has to be done before the TV turns on, or it can be done while it is on?

[tibimakai]

Re: LG 42LK450 no sound or hdmi

OK Bud, I have managed to switch the position and it works great with a 1K resistor and with the power supply.
Now, there are at least two points where I have measured 3.3V on the T_Con board. I have used one of them, it's a pretty big SMD diode, I have wired directly to that point and it didn't like it, it was vibrating.
Then, I have installed the 1K resistor and the screen is not flipping this way.
What am I doing wrong?

[tibimakai]

Re: LG 42LK450 no sound or hdmi

I have soldered the wire directly to the second spot, which looks like a regulator or FET and it works great.
The question is, I can leave it like this, or it needs some resistor?

[jbt2012]

Re: LG 42LK450 no sound or hdmi

LG TV have bad solder on the main board, This is my trick for many mainboard problems.
Place the main board in a preheat oven at 385 degrees for 10 mins. Turn off the oven and open the door a bit to let the oven and board cool. Then re-install the main and see if you issues are solved. I have been about 75% sucessful. ( What you have accomplised is a solder reflow of the main board. Good luck.