lg 50pb560b blinking red light only

[hispeck]

Hello Friends,
i just received this tv from a customer, it came with red light blinking only, after i unscrewed it and did my voltage test, i found two 30f133 / one smk 0460/ one smd diode G5, after replacing them set didn't come up, so i continued my test and discovered on the ysus around the small transformer there is a test point of +15vf and +5vf, but the both test point is given me 137v but one strange thing is that when the flat cable linked to the ctrl board is connected to the ysus, the said voltage will start to move back and fort, i also found out that the big IC on the ctrl board is hot,
the green light on ctrl board is not on, before i foget, vs 200v va 55v and 18v m5v all ok. schematic and heil is welcome please
hispeck

[Le Fils du Boulanger]

Re: lg 50pb560b blinking red light only

Good evening, I had a similar problem with the same model. By checking the Y-SUS board, I discovered a 30F133 in short circuit. I replaced it and turning on the TV, it started but the screen was flashing. No image was displayed, no sound, not even the logo at startup and the led of the logic board did not blink. By removing the LVDS ribbon, the led of the logic board turned on and no picture always. The + 15V and + 5V voltages are present and stable on the test points near the Y-SUS transformer. I read somewhere that you can do an automatic test of the logic board by making a strap between the holes near the resistors R541-R542, the LVDS ribbon removed from the logic board and next, turn on the TV, you should have bares color scroll on the screen. Which means that the logic board is good. You must change the main board.

Sorry for my english