How can I find out whats wrong with my TV?

Those blinks are error codes. Count the number of blinks and go on line with the make and model no. of the TV and number of blinks. For example (Sony Trinitron 46xxxxxxx 4 flash error code ). This will tell you whats wrong with the TV.

I thinks you need use a new power board instead of the old power board ,you can have a look https://www.abctay.com ,you may find what you need.

most likely the problem is if your lg tv is between 40 and 50 inches that the internal LEDS have gone bad typical with LG models you need to replace the LED light strips inside the panel and it is not easy to do unless your experienced with this take it to a shop or see the link below for more info LG 39 LED TV Model 39LN No Backlights Bad LEDs How To Replace LED Strips

You were looking for "led sound picture". You might be interested in the following threads :

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It sounds as if either the supply to the LED panel is faulty or an open circuit to the supply. What input do you have on the unit? DVD/CABLE?

LG 42LS5700 - LG.com

www.lg.com > Home > Support > Product Support

LG ElectronicsTV/Audio/Video; TVs; 42LS5700 ... TV Support Landing Page - HDTV/Netcast/webOS 1.0/webOS 2.0 ... Adjusting Picture Settings - webOS 2.0 Video ... quality and convenience of complimentary shipping when buying directly from LG.com. ... Curved TVs · 22 Inch to 29 Inch Class TVs · 32 Inch to 39 Inch Class TVs · 40 Inch ...

Amazon.com: Customer Reviews: LG 42LS5700 42-Inch ...

www.amazon.com/LG-42LS5700-42-Inch.../B006ZH...

Amazon.com, Inc.LG 42LS5700 42-Inch 1080p 120Hz LED-LCD HDTV with Smart TV (2012 Model). byLG. Size: 42-Inch ..... images are nice and crisp when viewing HD content.

Widescreen TV Black Screen - Repair LCD LED PLASMA ...

? 3:41
https://www.youtube.com/watch?v=RbZncfiOXQA
Jul 13, 2011 - Uploaded by FixItUrselfDummy
Fix your tv with black screen blinking light, popping sound noise. ... Watch QueueQueue ... TV Black Screen - Repair LCD LED PLASMA - Problems SONY LG .... I have a 60 inch samsung DPL tv how can I stop the humming or ... What do I do if my tvturns on but its just a black screen so sound no picture?.

Your problem is most likely a fried circuit board. I always connect my good electronic to a back up battery. but your problem might have been storm or surge related, I would take it to a repair center and get an estimate.

suspect either a back light power board issue or main power board to back light board issue...also, is it under warranty ?

REPLACED MANI BOARD
Manufacturer LGE Part Number EBU39191501 Description MAIN TOTAL ASSEMBLY