Power Trouble with LG 47LN549e-UA with ezsign software

[Thetallman72]

Im working on 2 LG TV's model numbers 47ln549e-UA. They will turn on then flash the LG logo, then turn back off. The indicator light will flash 3 times. Ive replaced the power supply board in one to no avail. Voltage readings seem normal but i cant find the service manual for this model anywhere so im not sure if the voltage going to the backlights is correct. I also cant find an error code guide for LG tvs. I was thinking it may be bad LED strips but since its both tvs (they are from a restaurant,went bad at the same time) im wondering if its an issue with the ezsign software. Would like some advice before I undertake the difficult task of led strip replacement. Any thoughts are appreciated. Thank you

[dick_barton]

Re: Power Trouble with LG 47LN549e-UA with ezsign software

What voltages do you have on connector P201 and led connector P801 and do you have a sharp photo of the power supply?

[Nick's Tvs]

Re: Power Trouble with LG 47LN549e-UA with ezsign software

You probably have back-light issues.

Try the flashlight test. Once you turn the tv on, let it initialize for 10 seconds, and then press the menu button. Now with a flash light at a 45 degree angle about 2 inches away from the screen, try to see if you can see the menu appear A dark room is usually ideal. If you can still see picture on screen then you have bad LED's

[budm]

Re: Power Trouble with LG 47LN549e-UA with ezsign software

We need good clear pictures of how all the boards are connected together and the details DCV readings of the power supply board connectors.

[Thetallman72]

Re: Power Trouble with LG 47LN549e-UA with ezsign software

Already had done the flashlight test. Couldn't see anything. Here are the voltage readings. This is a brand new power supply as well.

P201

1= 3.3 10= -.002
2= 3.5 11= .008
3= 3.5 12= .010
4= .005 13= 12
5= 0 14= -.005
6= 24.24 15= 24.61
7= -.003 16= 1.091
8= 12 17= 1.71
9= -.004 18= 3.25


P801

1= 26.61
3= 73.61
5= .062
7= 107.51 (this voltage would start high and drop quickly and steady aftet power button is pushed)

[dick_barton]

Re: Power Trouble with LG 47LN549e-UA with ezsign software

Can you tie the readings to the pin outs which would be helpful. For example:-

Pin1 (GND) = 0V, Pin2 (GND) = 0V
Pin3 (12V) = 12.2V, Pin4 (12V) = 12.2V
etc


The led voltage looks as though it should be 100V and if falling is probably a faulty led.

[vinceroger69]

Re: Power Trouble with LG 47LN549e-UA with ezsign software

in post one you say both tvs went bad at the same time if this is correct could it be a power surge issue though a input cable/aeriel etc?

[Thetallman72]

Re: Power Trouble with LG 47LN549e-UA with ezsign software

in post one you say both tvs went bad at the same time if this is correct could it be a power surge issue though a input cable/aeriel etc?

Possible. I was also wondering if it is tied to the fact it has ezsign software. It turns the TVs into marquee signs for businesses. These were used at a restaurant for that. Could the program possibly run the LEDs too high causing them to burn out? And i will tie the voltage ratings to the pins later this afternoon when i get home.

[dick_barton]

Re: Power Trouble with LG 47LN549e-UA with ezsign software

The leds have probably been at maximum brightness displaying the on screen messages and have most likely failed.

[Thetallman72]

Re: Power Trouble with LG 47LN549e-UA with ezsign software

The leds have probably been at maximum brightness displaying the on screen messages and have most likely failed.

I was starting to think that as well. I just wanted to be sure before ordering new LED strips. though it is starting to look like that may be my best option. Any preferences on sites to order from other than shopjimmy and TVchop shop.(besides Ebay)

[vinceroger69]

Re: Power Trouble with LG 47LN549e-UA with ezsign software

shopjimmy now do kits with all you need tools/replacement leds and lens at a resonable price too maybe look on there site led repair kits.

https://www.youtube.com/watch?v=EZVQ...hleuNO&index=1

[dick_barton]

Re: Power Trouble with LG 47LN549e-UA with ezsign software

Test the leds first to find any faulty ones as discussed in many threads in this forum. You could possibly use leds or led strips from one set to complete a repair on the other.