Lg 32lb650v no video,no audio, nothing

[daroo]

Hi, I have this LG TV that doesn't work.

When I plug a/c cord nothing happens, except the stand-by led that flashes 4 times (the first blink is faster than the others).

I have tested the voltages on the power board and everything is fine.

Is there something I can check to find the problem?

[budm]

Re: Lg 32lb650v no video,no audio, nothing

Hi, I have this LG TV that doesn't work. When I plug a/c cord nothing happens.

I have tested the voltages on the power board and everything is fine.

Is there something I can check to find the problem?

Please clarify as to 'everything is fine'.
Are you saying you have all the correct output Voltages and Control Voltages, correct PFC Boosted Voltage?
Please report the Voltage readings of all the pin on that black connector that goes to the main board, makes sure to put down the pin name and follow by the Voltage reading when TV is OFF and when the power switch is activated, please follow the instructions so we do not have to guess since we do not have the TV/ Boards in front of us to look at.
I.E.
PWR-ON: TV off = xxV, TV on = xxV

[daroo]

Re: Lg 32lb650v no video,no audio, nothing

Hi, I have tested the voltages, I can't test it with tv turned on because it doesn't stay on.

GND 0
12V 12,01v
12V 12,01v
GND 0
24V 24,6v
GND 0
3,5V 3,5/3,6v
3,5V 3,5/3,6v
PWR ON 3,4v



GND 0
N.C. 24,6v
12V 12v
GND 0
24V 24,6v
N.C. 2,1v
3,5V 3,5v
P-DIM 2,1v
DRV-ON 3,5V


thank you!

[Andrew F. Ali]

Re: Lg 32lb650v no video,no audio, nothing

From the reading you have posted it would appear the PSU and Main Bd are OK. Post pictures of the boards and maybe we may be able to help further.

[daroo]

Re: Lg 32lb650v no video,no audio, nothing

I have already posted pictures of the boards, you need the back of the two boards?

Thanks

[Andrew F. Ali]

Re: Lg 32lb650v no video,no audio, nothing

OOPS!!..I missed that. OK so with the TV OFF, place the RED probe of your DMM on the +ve pin of the backlight connector and the BLACK probe on the chassis GND. Turn on the TV and record and post your findings. Then place the RED probe of your DMM on the -ve pin of the backlight connector and the BLACK probe on the chassis GND. Turn on the TV and record and post your findings.

[daroo]

Re: Lg 32lb650v no video,no audio, nothing

on the +ve pin when I plug the cord I read 0,1 for a second and then it jumps to 144,5v.
on the -ve pin i read 0,1 for a sec and then 0.

[Andrew F. Ali]

Re: Lg 32lb650v no video,no audio, nothing

You have a bad backlight issue. One or a few of the LEDs on the backlight strips are open/short. You would have to tear down the Panel to get to the backlights. Are you up for the challenge?

[daroo]

Re: Lg 32lb650v no video,no audio, nothing

I have already done it with a philips tv, in that case i just shorted out the pads.

now i will disassembly the tv and check how many leds are faulty

[Andrew F. Ali]

Re: Lg 32lb650v no video,no audio, nothing

I would recommend a total change out of the strips. The seemingly good ones tend to fail not too long afterwards and you'll have to tear her down again.