Re: LG 32LN578V No Backlight

OK I worked up the courage to disassemble the screen, having never done it before.
And I discovered it's actually not too daunting a procedure.
So I have one bad LED strip, which I have now ordered.
Thanks for all your help guys - Peter

Re: LG 32LN578V No Backlight



Ah now that is very different - I was measuring between the LED + and - previously and getting nothing. Measured from chassis to LED + gives 125V regardless of LEDs being connected or not....

Re: LG 32LN578V No Backlight

I see no flashing at all on screen. It would be nice to know for sure before ripping the screen apart - is it possible to connect an equivalent load to check that the circuit powers up?

Re: LG 32LN578V No Backlight

Thanks for your reply.
I don't have that function on my meter.
It would appear that something happens when I power on - I get a couple of flashes of a reading on the meter, but nothing stable enough to read,

I got this TV free from someone who had this problem - namely sound is OK, but no picture.
With a torch I can see the LG logo on powerup and there is sound when I plug in a HDMI source, so it can't be too bad, I thought.
The guy who gave it to me had bought a replacement power board, but that behaves exactly the same way.
So I metered the connector from the power bd to the main bd.
Main voltages are OK. However there are three lines whose function I don't understand:
pwr on 3.5vdc 6.4vac (I measured with the multimeter set to DC and AC)
drv_on 3vdc 5.7vac...

Re: LG 32LN578V PS b/d issue

New user here, so maybe I should be opening a new thread rather than replying here.

There are a couple of threads on this model, with similar problems, which I have read.
However, this is my first time troubleshooting an LED TV, so I'm a little lost.
I got this TV free from someone who had this problem - namely sound is OK, but no picture.
With a torch I can see the LG logo on powerup and there is sound when I plug in a HDMI source, so it can't be too bad, I thought.
The guy who gave it to me had bought a replacement...

Re: New Members - please post your introductions here

Hello, I'm Peter fro Ireland - retired computer engineer, currently trying to fix an LG TV