LG 19" TV - No backlight

[dtax]

Hi all!

I have a 19" no-name brand TV which backlight just stopped working. The TV is sold under many different cheap brands (Bush, Dantax etc.) but internally it's all LG.

Here's a link to my model:
http://www.ricability-digitaltv.org....0LED19916DVDHD

The TV will turn on and the sound is working perfectly. I can also see that the picture is there, if I hold flaslight across the screen. So the backlight is not working at all, it doesn't even blink when I turn the TV on.

I've opened the case and checked the internals and think I might see where the problems is, but would like to ask for some advice what to check before ordering parts.

I've taken pics from the inside. I can't see where the inverters are located, as these are usually the cause of such a problem. If you check the pic of the mainboard that I've attached, you can see that connected to it is a small add-on board (the brown/yellowish PCB adaptor with the coil, diode and a cap) which I think is toast. Right below the coil on the front side you can see a dark spot, and on the other side at that same location is a small chip with a similar dark spot around it and especially two of it's legs. This is probably fried completely?

I found a replacement board here:
http://www.chsinteractive.co.uk/elec...05-alba-lg.htm

But before ordering that, I just wanted to confirm if I should check anything else? The PSU is on an external brick, model number is DA-48M12 which I've checked to be outputting 12V from it's pins. Couldn't open it though to check it's caps, but would there be any need to?

Thanks to everyone in advance!

[Rtech]

Re: LG 19" TV - No backlight

As yet I have not been able to get myself into the LED models, which this one is ?? and so an Inverter is a non requirement I suspect,as no doubt DC only drives the backlight leds.As far as the Power Supply (brick) is concerned, you can get the case where you can measure the voltage with a meter, BUT as soon as current is drawn it drops off,usually due to badcaps.Your fault sounds like the small board,or a failure of the leds themselves,the former being my guess

[dtax]

Re: LG 19" TV - No backlight

Thanks for your input Rtech!

You're absolutelly correct, this is a LED model. So that explains the "missing" inverters.

Would there be any point in measuring the output connector of the small board? It's the white one on the lower left corner of the small board, the thinner cable from the display units driver board (or whatever it's called) connects there and gives power to the display (just a guess...). It's a 4-pin connector, but I have no idea how and which pins I should test.

I'm just thinking if these pins don't output any voltage to the display unit, that would probably narrow LED problems out since they aren't getting any power in the first place?

[Rtech]

Re: LG 19" TV - No backlight

Normally some indication of what voltage etc should be on particular pins of connectors is printed on the board itself,if yours has no markings then you are up the creek without a paddle,so to speak !!