Lg42lw450u back light and sound good. No picture.

[Cobblers]

Hello all. Im trying to work out wether this tv is worth saving. Like the description says i have sound but no picture. I disconnected the ribbons from the t con to the lcd one a a time.

With the lh one disconnected looking from the back i get half a screen display the other half white. With the rh ribbon disconnected i just one side of the lcd slightly darker than the other but no obvious image.

If you need any more info let me know. Ive took pics of my tcon board and the screen from testing it. Ive search the forum and found a similar case, but the photos of the screen looked different.

[Diah]

Re: Lg42lw450u back light and sound good. No picture.

T-CON fault, ob is repairable i dont think so, but before you start with finger touch on ices on it to check if any goes warm, if not then just reheat the big ic in the middle with hot air gun. or backing it .

[ReeceyBurger123]

Re: Lg42lw450u back light and sound good. No picture.

Doubt its Tcon normally panel fault which is not fixable. Wait and see what others think but 90% of the time this is not fixable.

[Diah]

Re: Lg42lw450u back light and sound good. No picture.

Panel made by LG self, the 12 volts to turn panel on it keep on the side which had no contact with T-CON. this why it look white by no signal and the other left being white too when no signal,

[ReeceyBurger123]

Re: Lg42lw450u back light and sound good. No picture.

He dissconected the one side which gave full white (half Lcd open due to other side having votage applied) but when the one side is disconnected its dragging down the Tcon there for meaning the panel is probably shorted. Not fixable IMO.

[Diah]

Re: Lg42lw450u back light and sound good. No picture.

He dissconected the one side which gave full white (half Lcd open due to other side having votage applied) but when the one side is disconnected its dragging down the Tcon there for meaning the panel is probably shorted. Not fixable IMO.

Take look at LG service manual this fault called Noise , replace T-CON

[michael dranfield]

Re: Lg42lw450u back light and sound good. No picture.

He dissconected the one side which gave full white (half Lcd open due to other side having votage applied) but when the one side is disconnected its dragging down the Tcon there for meaning the panel is probably shorted. Not fixable IMO.

I have had this before , half the screen dragging down the voltage and I suspected a Leakey ceramic capacitor on the screen connecting board, but with nothing to lose and now wanting to disassemble the screen I just appiled 12 volts at 10 amps to the rail dragging down the voltage and after a puff of smoke the set came on fine, so I am assuming it was a leakey MLCC on the connecting board and it just burnt up and went o.c. but the set never came back again.

[ReeceyBurger123]

Re: Lg42lw450u back light and sound good. No picture.

Possibly, I have seen the tab drivers fail which causes this they drag down the B+ from the Tcon causing it to shut down.

[michael dranfield]

Re: Lg42lw450u back light and sound good. No picture.

Possibly, I have seen the tab drivers fail which causes this they drag down the B+ from the Tcon causing it to shut down.

Quite right, but when you have nothing to lose and the customer says if its not worth repairing you can keep it and they will get a new one why not give it a go !

[Cobblers]

Re: Lg42lw450u back light and sound good. No picture.

Ok well thanks for the advise. I will probably get a t con board aa there not too expensive.

I was wondering if both sides of the lcd connectors are wired the same way around so i could cross connect the lcd ribbons to see if it reverses the fault from right to left if you understand what i mean.

So i would connect the right hand lcd ribbon connector to the left hand side of the t con?

[Diah]

Re: Lg42lw450u back light and sound good. No picture.

don't do this ,

[ReeceyBurger123]

Re: Lg42lw450u back light and sound good. No picture.

You just going to waste money IMO seen to many not be fixable. Keep us updated.

[adamp91gvm]

Re: Lg42lw450u back light and sound good. No picture.

If you dont fix this ill buy the av board if its the one i need

[finntricky]

Re: Lg42lw450u back light and sound good. No picture.

i had the same fault with the same tv a few months back, and thought it was t-con, but no, it was a bad screen.,

[finntricky]

Re: Lg42lw450u back light and sound good. No picture.

If you dont fix this ill buy the av board if its the one i need

i have a main board from the set here if you need it, as i stripped mine down

[Cobblers]

Re: Lg42lw450u back light and sound good. No picture.

Ok so i stripped the set back a bit further. I took the screen bezel off and the metal cover from the base of the panel.

I found what looks like possible moisture damage well thats what it looks like to me. but also there could be a component missing.

So what do you all think? It is on the bad side of the screen.

[Diah]

Re: Lg42lw450u back light and sound good. No picture.

water damage, still you can try to clean it, and dry it and check all caps if no short hat, you can still stry to replace thr R , you can read it value from other line. , you will not lost any as it is scrap

[budm]

Re: Lg42lw450u back light and sound good. No picture.

One of those LCD panel with tab bonding board on the bottom edge of the panel, people will spray cleaner on the screen to clean the panel and those liquids just seep do to the boards and caused problem. So it is bad panel problem as reece had indicated.

[adamp91gvm]

Re: Lg42lw450u back light and sound good. No picture.

Anyone still got av boards for this tv

[sordids999]

Re: Lg42lw450u back light and sound good. No picture.

ive got one at the moment