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Equipment Repairs => LCD TV forum => Topic started by: Davy on January 27, 2020,08:45:14

Title: LG 42LN543V Stby comes on give's one wink and out
Post by: Davy on January 27, 2020,08:45:14

Have a LG 42LN543V telly, LED comes up one flash and then goes out , all the voltages are up, but the 24V to the main board is only 23.4V, I've change the small 100u 50V capacitor and still reads same, not having the service manual I assume this is for the audio amp. since the LED has it's own inverter, any clue on the error code, the standby comes up then winks and goes out.

Is it the screen LEDs or the mainboard? Thanks.

Dave

Title: Re: LG 42LN543V Stby comes on give's one wink and out
Post by: downunder on January 28, 2020,01:23:16

Hi Dave,
LG main boards are notorious for dropping the BL-ON (INV-ON) voltage to the power supply to activate the backlights. So check if this voltage (about 3V) is present at the power supply connector. If no, probably bad ball-joints under the micro.

If yes, probably a bad LED or centre connector on the LED strips. I doubt the 23.4V will make any difference in the scheme of things. When you fix it, you can go into the "Power Off Status" by pressing IN-STOP on the service remote and selecting Power Off Status from the menu. This gives you the cause for the TV shutting down.

Bruce

Title: Re: LG 42LN543V Stby comes on give's one wink and out
Post by: Davy on January 28, 2020,12:13:50

Hi Bruce,
The inverter is producing, my guess it's the back lights...  funny why I hadn't thought about this before posting, removing the BL plug makes no difference to the voltage so that means one thing the telly's a scrapper now so will consider pulling the screen apart and consider the viability of swapping the strips, might as well do em' all if it is the LED's to save hassle later.

Dave

Title: Re: LG 42LN543V Stby comes on give's one wink and out
Post by: sinclairtv on January 30, 2020,15:15:04

110% faulty LEDs

Title: Re: LG 42LN543V Stby comes on give's one wink and out
Post by: Davy on February 05, 2020,12:46:26

Quite right the LEDs... two strips faulty.

Dave