lg42lg7000-za schematic needed

[snipersquad100]

Hi guys, I got a LG 42LG7000-ZA TV to fix tomorrow and she wants it back by the 19th for her sons birthday. Problems sounds like bad caps, I just wanna see a schematic to see what value caps it has so I can check if I got some in stock.
thanks

[multimeter]

Re: lg42lg7000-za schematic needed

try here http://www.toms-service-manuals.com/

[snipersquad100]

Re: lg42lg7000-za schematic needed

thankyou multimeter

[snipersquad100]

Re: lg42lg7000-za schematic needed

umnot one there

[snipersquad100]

Re: lg42lg7000-za schematic needed

ok, I've got the tv open, Caps seem fine on the esr meter.
the power supply took a bit of time to turn on but when it did I had all the voltages but nothing on screen.
any ideas where I go from here?

[snipersquad100]

Re: lg42lg7000-za schematic needed

should I have a PWM DIM voltage cos I don't.?

[multimeter]

Re: lg42lg7000-za schematic needed

urm..what is wrong with it??symptoms?

[budm]

Re: lg42lg7000-za schematic needed

"the power supply took a bit of time to turn on but when it did I had all the voltages but nothing on screen.
any ideas where I go from here?"
More details such as backligts are on or not, PS_ON, BL_ON, 12V, 24V 5VSTB voltage readings? Pictures of the boards?

[tom66]

Re: lg42lg7000-za schematic needed

Would make a note than an LG7000 is a fairly new TV (2009?) that would be unlikely to have bad cap issues -- that's really the stay of Vestel and other such junk now.

[snipersquad100]

Re: lg42lg7000-za schematic needed

ive tested the caps and they ok. but im not getting an pwm-dim signal from the main board. I've found out that the pwm-dim drive chips get very hot on this type of board.

[tom66]

Re: lg42lg7000-za schematic needed

What is a PWM-DIM drive chip? Not heard of one like that.

[snipersquad100]

Re: lg42lg7000-za schematic needed

seen it on you tube, t-con boards with two ldvs cables the pwm-dim chips get hot.

[tom66]

Re: lg42lg7000-za schematic needed

Possibly the MOTION FRC for the 100Hz? Or for FULL LED TV, the dimmer control chips.

[snipersquad100]

Re: lg42lg7000-za schematic needed

Am I right in saying that if I have no pwm-dim coming from the main board that it needs replacing?

[tom66]

Re: lg42lg7000-za schematic needed

Do you have any PS ON, or BL ON/OFF?

[snipersquad100]

Re: lg42lg7000-za schematic needed


nc ov
pwm-dim 0v
on/off 4.5v
acd 5.1v
gnd
gnd
5v = 5.1
5v= 5.1
gnd
12v = 12.2
gnd
16v = 16.1

[tom66]

Re: lg42lg7000-za schematic needed

Try disconnecting the PWM-DIM line from main board end, and connect it to a 5V line with a 100 ohm resistor in series, does backlight light up?

[snipersquad100]

Re: lg42lg7000-za schematic needed


error is 0v
pwm-dim is 0v
on/off is 4.5v
bri is 0v

[snipersquad100]

Re: lg42lg7000-za schematic needed

how can I just disconnect the pwm line ? its in the plug with all the other voltage lines.

[tom66]

Re: lg42lg7000-za schematic needed

Cut the wire approx mid way through, in such a way that it can be reconnected.