Lg 42ld550v

[kolls1]

I am trying to make the backlights to come, and the way I understand I need to unplug connector to main board and put 3.4 volts to pwr on and also inv on/off , is that correct ?

[budm]

Re: Lg 42ld550v

Please attach good clear pictures of the boards for us to look at.
You should use 470 ~ 1K resistor between 5V (3.3V) standby power supply output and the control pins, I.E. PS-ON and BL-ON (some time the Dim may be needed too) without main board connected.
But at this point with all the cables in place, what Voltages do you have on the control pins?

[kolls1]

Re: Lg 42ld550v

NC 0.1 / Error 0
12v 0/ P-dim 0
12v 0/ A-dim 0
12v 0 inv on,off 0.05
-
-
3.5v 3.4/ 3.5v 3.4
3.5v 3.4/ 3.5v 3.4
-
20v 0/ 20v 0
On 3.2/ 20v 0

when i hit the power button, 0n pin has 0 then once i hit the little black button on the main board i get 3.2 on but no other voltage, the led just flashes slowly,

[nomoresonys]

Re: Lg 42ld550v

You did not label the pins, see if there's a legend/map, list the voltages with tv plugged in but off which is standby then power on tv, see what the voltage does, report both conditions here, don't forget to label the pins, ps-on, 12 volt, gnd, stndby etc.

[budm]

Re: Lg 42ld550v

"NC 0.1 / Error 0
12v 0/ P-dim 0
12v 0/ A-dim 0
12v 0 inv on,off 0.05

So you are not getting Dim control or BL-ON (INV ON) control signals.
I do not know if ERROR signal is supposed to be normally HIGH or normally LO for normal condition.