LG32LN350B Won't start

[Decoop]

Little history on my problem the TV started having to be unplugged to startup every 2-3 days and gradually got worse to the point it would not startup. Currently the LED on the front of the set will flash two times and go out. As I said before when it did this I could unplug it for a few seconds and when I plugged it back in the led would stay on and the set would start up.
So far I have checked diodes and transistors for shorts the fuse is ok and voltages on the PS are as follows with the PS connected.
12v- 12.0
12v- 12.0
Grd
24v- 23.5
Grd
3.5v- 3.4
3.5v- 3.4
PWR-ON 3.2
All measured from chassis ground.
Measured across C109 +- 160-165vdc not stable
Measured across C110 +- 162-165vdc not stable
Next steps??
Attached pics
Can't figure out how to post more than 1 pic.

[budm]

Re: LG32LN350B Won't start

There are missing signals that you did not post: The BL-ON , the PWM DIM/DIM signals. You need to check those signals.
We also need the pictures of the whole backside of the TV that shows all the board when you are able to upload the pictures.

[Decoop]

Re: LG32LN350B Won't start

All of the capacitors look fine no visible bulging or leaking.
Adding pic of other board

[Decoop]

Re: LG32LN350B Won't start

Not sure where to check BL-ON and PWM DIM/DIM signal

[budm]

Re: LG32LN350B Won't start

The connector on the power supply board that goes to the main board has label for each pin, you need to list them.

[Decoop]

Re: LG32LN350B Won't start

I listed them as labeled in original post. Top to bottom as seen in the attached picture.
I think that's what your asking

[Hamie]

Re: LG32LN350B Won't start

it's an 18 pin connector.
You've listed 8 voltages.


Take a picture of this legend table:

[budm]

Re: LG32LN350B Won't start

Also please clarify the TV model number, you post it as 'LG32LN350B'

[Decoop]

Re: LG32LN530B won't start

Ok let me try again sorry about that

GND--
12V-- 12.0.
12V-- 12.0.
GND--
24V--- 23.5.
GND--
3.5V-- 3.4.
3.5V-- 3.4.
PWR ON 3.2.

GND--
N.C.--
12V-- 11.9
GND--
24V-- 23.4
GND--
N.C.--
PDWI-- 0
DRV-ON-- 0.1

All DCV measured from chassis ground
Attached better pic of 18 pin plug
Model number 32LN530B-UA looks like I had it 350 I'm not helping much.

[budm]

Re: LG32LN350B Won't start

The main board is sending the PWR-ON signal to turn on the main power supply and the power supply is putting out the switched Voltages, but the main board is not sending the PDWI (PWM backlights Dimming) control signal, it is also not sending the DRV-ON (BL-ON/INVR-ON) to turn on the backlights circuit.
So the main board is not working or something is locking out those two signals.
You can try forcing on the backlights to see if the backlights will come on and be able to see the pictures on the screen, if you are able to force the backlights on but still no pictures then you have more problems on the main board beside the missing two control signals.

[Decoop]

Re: LG32LN350B Won't start

So you suggest replacing main board??
Where is the best place to look for one??

[Hamie]

Re: LG32LN350B Won't start

Connect pwr-on to drv-on with a piece of wire and see if the back lights come on and you get a picture.

[Moreno83]

Re: LG32LN350B Won't start

Will this also work for any led/lcd? ( pwr on to drv on )

[Decoop]

Re: LG32LN350B Won't start

Jumped PWR-ON to DRV-ON back lights flash when first plugged in then go off.
Voltage drops from 3.2 to 3.08

[Hamie]

Re: LG32LN350B Won't start

Also connect 3.2v to pwi.

[Decoop]

Re: LG32LN350B Won't start

Ok back lights are on and running didn't hook any video source to it if I do should audio and video work??

[Decoop]

Re: LG32LN350B Won't start

Ordered replacement main board from EBay installed today and it is back up and running.
Thanks everyone for your help.