LG 42LG3000 Backlight for 2 sec

[Parre]

Hi.

I have been reading a whole bunch of thread here on Badcaps.com about tv repairs but i just can't find the fault on my LG.
When i turn the tv on it starts as expected by showing the channel number in the upper right corner but about 1 or 2 seconds later the backlight fades and it turns black. By pointing a flashlight at the screen i can still see the channel number.

I have desoldered every single capacitor and meassured capacitance but not the ESR as i do not have the right equipment. The caps seems to be fine though with the right capacitance and no visual error.

I have resoldered some bad solder points on the blacklight inverters as well with no success.

I may try to buy new caps and replace them all but i am hoping that you might have some tips on how to solve this.

I attached a few pictures to show the boards and a video to show how the tv behaves. http://youtu.be/buCtI47IUzc

[Alessio]

Re: LG 42LG3000 Backlight for 2 sec

Same here

[richpart]

Re: LG 42LG3000 Backlight for 2 sec

I have a stupid question? Did you try to update the firmware yet? (Version_03.55.01)

Available here http://www.lg.com/ie/support/product...initialTab=faq

Service manual trouble shooting section states as follows:
This board has big problem because
Main IC(IC100) have some troubles.
After checking thoroughly all path once
again, You should decide to replace
Main Board or not.

[tom66]

Re: LG 42LG3000 Backlight for 2 sec

This is probably 2 seconds to black, so check the BLON signal on mainboard to see if it is main board or inverter/PSU/bulbs.

[apocalip]

Re: LG 42LG3000 Backlight for 2 sec

tom66: could you please describe how to check the BLON?