Re: LG 42LE2R with the '2 seconds to black'


When I unplug the cables from Power board to main board the TV doesn't respond, the status LED is not comming up and even the relay on powerboard is not activated. When I plug it back you hear the relay on powerboard activating and TV goes into standby mode.


I assume it's either the backlights with a problem or the inverter boards.
On the inverter boards I already replaced the mosfets Q14,Q15,Q18 and Q19, I checked a lot of SMD capacitors and the 2 electrolytic caps and all looks fine, I just didn't...

Re: LG 42LE2R with the '2 seconds to black'

Hi,
You mean the main power board or the inverter boards?
The main power board has 2 connectors for the inverter boards with proper 24v when TV is ON. I don't think it's damaged.

Re: LG 42LE2R with the '2 seconds to black'

The Mosfets on the inverter boards are FDD8447L and they all read arround 3.5MOhm from S to D and G to D. From S to G they read 10kOhm.
I actually already replaced the ones on Master inverter board with new ones and keep getting same values Q15, Q14, Q18 and Q19.


Regarding the capacitors, you mean C15 and C19? When I start measuring them they are in the order of 200kOhm and start increasing until Mega Ohms.
In circut they measure 19uF (parallel).


Regarding the C16,C18,C1 and C62...

Hi all,
I have an LCD TV LG 42LE2R with the '2 seconds to black' issue.
When I first opened it I noticed some pregnant 2200uF capacitors on the Power supply board and I immediately replaced them:
[ATTACH]258236[/ATTACH]

But everything remained the same, so I started debugging.

On the Power supply board we have 2 connectors, one for each Inverter board (Master and slave), checking the voltage everything looks fine
[ATTACH]258235[/ATTACH]
24 Volts on all 24V pins, 2.7V on 'Bri' and 4.76V on 'Inv' when TV turned ON.

Next step was...

Re: New Members - please post your introductions here

Hi all,
My name is Rodrigo and I'm very glad to join this community of Electronic enthusiasts.
I'm a computer engineer but always had a soft spot for Electronic and DIY project.