No picture/sound, but front buttons turn on

rhbox

Honorable
Jan 28, 2013
1
0
10,510
I have a 47" LG LED TV (47LE5400) that seems to have suffered a power surge or something. When I press the touch sensitive buttons in the front, they all turn on, giving the impression the TV is turning on, but nothing ever come up on the screen and no sound comes out of the TV either.

Any suggestions as to what it may be or what parts might need to be replaced?

I've been told that the power supply should do the trick. Anyone agree/disagree?

Thanks to all in advance.
 

cgnthw

Estimable
Dec 16, 2014
1
0
4,510


Hello, I have same TV and same problem. Did you fix your TV?
If you have the solution, could you share it with me?
Thanks.
 

rohmrohm

Estimable
Dec 8, 2015
2
0
4,510
I have same model TV. I turn it on the LG logo and buttons light up like its on and I had no picture or Sound. If you open the back of the TV and goto the main board not the power board there is a little black button on the board.Press it and if you see the Leds flash on. Your power board and led drivers are fine.The symtoms you describe are Main board problems. I sent my board out for repair from an online tv repair company and for 100 they fixed it. My Tv now works Great.If you do what I explained to do and the leds Flash I see no reason why your Tv wont work after getting the main board fixed.At Least that the first step you would take with the symptom you describe.If you research online you will see that's the first step you take. If the leds don't flash on. your main board may need more repair than mine did.If you get the main board fixed and still same problem wich I doubt is going happen. I would then try the main board button test and if they don't flash then I would have the power board looked at but right now the light on the buttons come on so you do have power.Also see if the ethernet socket or any other kind of light is on.On the main board. If you do see lights on.on the main board. That would make me believe more that my power board is ok and its the Main board.I'm not an electronics tech by trade but a 30 yr electricians that does eletronics for a hobby.I'm telling you my story with my TV and hopes it helps you out.
 

rohmrohm

Estimable
Dec 8, 2015
2
0
4,510
ps:the T com board is not separate from the main board like others it built into the main board and the led drivers are built onto the power board not like others that have separate boards. The symptom you have. the first step would be the tcom board but being built into the main board you have no choice but to have the main board fixed.
 

cliffcat

Estimable
Dec 10, 2015
2
0
4,510


 

cliffcat

Estimable
Dec 10, 2015
2
0
4,510
hi rohmrohm and all others,
I have a 47le5500 which exhibits the same problem of no picture and no sound with the same symptoms of the front lights coming on. I think it has the same power boards and mainboard as they match the description of what you posted.

when you say the leds flash on are you meaning the backlight leds or the front panel lights along the bottom of the tv??

I looked at the main board and it has 3 pushbutttons. One is green and the other two black.
when i press the green button nothing changes

one of the black buttons is on the top left of the board and when i push it, nothing changes.

The second black button is located on the left center of the board, when i push it,, the power supply relays click and it shuts down, and i do not see a flash.


also the little led on the internet port does not light up

I disconnected the two cables the go into the top of the set that drive the backlight and repeated the button test and got the same results. the set shut down when i pressed the left center button
lookinng forward to any help



while i have been looking at this set for awhile i measured many of the power supply voltages and signals to and from the main board, They pretty much are within their ranges although not sure what is the active state of some of the handshake signals.
I