LG 47LG50 No Backlight

[neilc6]

Re: LG 47LG50 No Backlight

The backlights come on for a 5 second cycle with the small flex connector from the tcon removed.

I have enclosed pics of the PS connectors.

The question is will a different tcon fix this issue. The $15 one on ebay is untested.

I will check the tcon fuse once more and also see if the multiple error signals are connected together.

[vinceroger69]

Re: LG 47LG50 No Backlight

what voltage do you get on the t con fuse? i would probably take a gamble on the ebay tcon as if faulty you should still be able to return it?

[neilc6]

Re: LG 47LG50 No Backlight

With the tv in the "on" state with either the small flex connected (backlight flash) or disconnected (backlight cycles on), I get 12.4V on both sides of the fuse on the Tcon.

The ERR signal from the master inverter directly connects to the ERR signal on the connector on the PS board going to the main board so they are the same signal probably going to the main processor.

The $15 Tcon is sold as is from a recycler on ebay.

[vinceroger69]

Re: LG 47LG50 No Backlight

have you got a picture of the tcon in your tv it does seem odd your getting no picture at all are you getting sound on the tv or does it shut off too quick, looking at the pictures you posted it does look like one lamp maybe out

[neilc6]

Re: LG 47LG50 No Backlight

With the small flex connected back, the TV is now cycling. Two slow red front LED flashes and quick backlight flash repeating. Wasn't getting any menus before with small flex disconnected and backlight on and not sure about sound.

Would a burnt out CCFL tube NOT produce an error low signal?

Here is a pic of the tcon.

[neilc6]

Re: LG 47LG50 No Backlight

Decided to peek under the panel to see if all the bulbs are good. Carefully lifted up the corner and all bulbs were lighting up with the small flex disconnected. Guess it's down to the Tcon or main board. Searching V420H1-C07 finds a lot of Tcons with many under $20.

[vinceroger69]

Re: LG 47LG50 No Backlight

i think you also need to match as much of that white sticker details as best you can, as i guess they may all drive the panel different hopefully a more experienced member will advise

[attainteddragon]

Re: LG 47LG50 No Backlight

this is your t-con i believe.

http://www.shopjimmy.com/cmo-35-d020223-t-con-board.htm

[neilc6]

Re: LG 47LG50 No Backlight

this is your t-con i believe.

http://www.shopjimmy.com/cmo-35-d020223-t-con-board.htm

The shopjimmy link shows the part number 35-D020223 embedded in the sticker.

Worst case I sell the power supply board and break even.

[heavymachines]

Re: LG 47LG50 No Backlight

Decided to peek under the panel to see if all the bulbs are good. Carefully lifted up the corner and all bulbs were lighting up with the small flex disconnected. Guess it's down to the Tcon or main board. Searching V420H1-C07 finds a lot of Tcons with many under $20.

was any bulbs pinkish?

[neilc6]

Re: LG 47LG50 No Backlight

Got a used tcon installed and it behaves exactly the same way. A bit apprehensive about scrapping the TV and selling the boards since I don't know which boards are bad.

Bulbs looked all the same when I took a peek and not pinkish.

[neilc6]

Re: LG 47LG50 No Backlight

As an update, I sold both the power suppy and main boards with the buyers not reporting problems. So I either had two bad tcon boards or the inverter board had a problem.