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Mike G.
Mike G., Technician
Category: TV
Satisfied Customers: 7476
Experience:  10 Years Audio Video Repair & Setup
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I have two lg 47ln578v TVs bought at the same time both

Customer Question

Hi I have two lg 47ln578v TVs bought at the same time both now out of warranty 2013 build date . Both have failed in exactly the same way turn the TV on lg logo flashes up then blank screen sound ok remote ok put flashlight on screen and you can see picture so I presume it's a backlight issue ?? Is there a replacement board or part I can buy to repair them ?? Any assistance greatly appreciated.
Thanks Leigh
Submitted: 2 years ago.
Category: TV
Expert:  Mike G. replied 2 years ago.
Hello, my name is***** am an experienced electronics field technician connected to you via this pay for assistance chat based support service. Your satisfaction is my top priority and in return your positive rating is the only way I will receive credit for my time. To get started we need more information (additional details may be required):

Since this is a UK model, it makes things more difficult. Can you take the back off the tv and snap some pictures of the layout of the boards? Some more pictures of each board? Then attach them here in your reply.

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Customer: replied 2 years ago.

Ok I will take the back off may take me about half an hour or so to do

Expert:  Mike G. replied 2 years ago.
thanks
Customer: replied 2 years ago.

Expert:  Mike G. replied 2 years ago.
Thanks. No backlight symptom can either be the POWER/LED board or the actual LED's inside the Display Panel. If you have a meter you can test the voltages coming out of that board going to the Display Panel while the tv is running. If you don't have voltage then you need to replace that board. If you do have voltage then it's the LED's inside the Display Panel and you are pretty much done because it's not feasible to change the LED's inside the Display Panel. At least it is not something that tv repair shops will ever do, we just replace the entire Display Panel (but that costs more than a new 47 inch tv). I did find an eBay auction for this board:http://www.ebay.co.uk/itm/271958226339 If you can get some part numbers off your board, then you can use Google to search for other possible sellers. PLEASE, before you go be sure to click the POSITIVE RATING now. Doing so does NOT close the question or prevent us from continuing our conversation here. My livelihood truly does depend on your positive rating. Clicking the "bad/poor" rating does NOT issue you a refund. Thank you,Mike
Customer: replied 2 years ago.

Hi MIke so I have tested the board and the led feeds are the ones that are the four black wires in the white plug that is at top of this board between the four capacitors i get a feed of 77volts from each positive terminal when I power up but if I ground one of the negative terminals through my tester set to ohms the screen powers up a about half brightness also if the LEDs have gone why does the logo pop up as bright as normal when you power up

Expert:  Mike G. replied 2 years ago.
Great information. Unfortunately this means you have a short in one of the LED's inside the screen. But it's not much of a gamble to grab that $9.99 ebay item just to confirm.
Mike G. and 3 other TV Specialists are ready to help you
Customer: replied 2 years ago.

Hi Mike the one for sale on eBay has a number of EAX64905301 2.2 and mine is EAX64905501 2.2 but when I put my number in Google I struggle to find it would the one from eBay work?

Expert:  Mike G. replied 2 years ago.
Ya, if the ebay auction is giving that part number then it is not the correct one for your tv. I have found the exact match for yours here in the US. Don't know if they will sell to you:

http://www.shopjimmy.com/lg-eay62810801-power-supply-unit.htm
Customer: replied 2 years ago.

Decided it had to come in bits after looking on other forums got to be a bit carefull in the strip down but I've managed it 👍👍👍the reason the screen flashes up the logo is the initial power up but then it realises that some of the LEDs are blown and shuts down ......... Ahhh well think I will test the led strings find the good ones and hopefully make one good set from two 😀😀😀😀cheers ***** ***** I find a way of easily testing for an led failure without a complete strip down I will let you know

Expert:  Mike G. replied 2 years ago.
sure ok