LG 42LS3450 powers off

[Manddave]

Hi
I have a Lg 42 ls3450
The problem is it will not stay on it comes on for a short time and then powers off.
Can you help please
Many thanks

[Dgtech]

Re: LG 42LS3450 powers off

Post some clear pics of the boards inside.

[dkneyle]

Re: LG 42LS3450 powers off

I've just repaired an LG 42PJ350. I suspect it's close to the same set. It will be the power supply. Have a look for a 6 terminal regulator attached to a heatsink. It might have the same part number as mine did: 3BR1565JF. They seem to be notorious for failing the way you have desscribed. I assume all your electro caps on that board look OK? There's some high wattage low value resistors that fail, as well as a diode close to the 6-terminal regulator. But I reckon it will be that regulator. Let us know how you go. (By the way, those regulators are a couple of bucks on E-Bay.)

[tom66]

Re: LG 42LS3450 powers off

Your model is a plasma, his is an LED-LCD, unfortunately I doubt the power boards will be similar.

[dkneyle]

Re: LG 42LS3450 powers off

Of course Tom is correct! (I was trapped by the similarity of the model codes without having drilled down deeper.)

[angel-boy]

Re: LG 42LS3450 powers off

I ask here , i dont want to open another topic,

i have a problem with 42ls3450 display panel . see photo ,

problem with panel or t-con ?

[Alastair E]

Re: LG 42LS3450 powers off

Looks like AS-15,--If it has one....

[angel-boy]

Re: LG 42LS3450 powers off

have a TPS65178 , and in few seconds is hot

[tom66]

Re: LG 42LS3450 powers off

Unplug one ribbon at a time from the T-con (on the LCD panel side, not the LVDS cable.) If the TPS chip cools down or half the picture looks normal, it's probably a short on the panel and there's not much you can do about that.

[angel-boy]

Re: LG 42LS3450 powers off

i try this, i remove one ribbon ar a time , but no image right or left side, only vertical lines

[michael dranfield]

Re: LG 42LS3450 powers off

Unplug one ribbon at a time from the T-con (on the LCD panel side, not the LVDS cable.) If the TPS chip cools down or half the picture looks normal, it's probably a short on the panel and there's not much you can do about that.

I have had this exact fault on an LG TV with the LCD bias IC getting hot and un pluging one side of the ribbon cable did indeed cure the fault , however sometimes this problem can be nothing more than a smd ceramic decoupling capacitor on the LCD connection board and with nothing to lose I applied 12 volts at 10 amps to the board power feed and in the blink of an eye something went up in smoke and the short was burnt away , so I am assuming it was just a decoupling capacitor.So worth thinking about if you have nothing to lose and dont want to disassemble all the panel to fault find the connection board.