LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

[JDC]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

Where are the pin numbers?
TV off
Pin 1 = ???
Pin 2 = ???
Pin 3 = ???

TV ON
Pin 1 = ???
Pin 2 = ???
Pin 3 = ???

I posted it as if you were looking directly at it. Given that, Pin 1 is the upper left pin, Pin 2 is the upper right pin, Pin 3 is the center bottom pin.

As for the -14.44, I measured Ohms while the TV was plugged in and on. I now know that was incorrect to do.

[JDC]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

Okay, I need to slow down.

Given the pinout you put into my picture:

off

Pin 1: .006
Pin 2: 0
Pin 3: .005


ON


Pin 1: 1.784
Pin 2: 12.11
Pin 3: 12.11

[budm]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

Okay, I need to slow down.

Given the pinout you put into my picture:

off

Pin 1: .006
Pin 2: 0
Pin 3: .005


ON


Pin 1: 1.784
Pin 2: 12.11
Pin 3: 12.11

So pin 2 is the output pin and it shows 12.11V so the switched transistor is working, now as I request the resistance reading of L1100. What resistance do you get, <1 Ohm? Right now I suspect that L1100 has open circuit.

https://www.badcaps.net/forum/attach...0&d=1461687797

[JDC]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

L1100 shows .001 ohms (with neg probe on one side, pos on other, TV unplugged).

[dick_barton]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

So you should then have 12V dc on that side when you switch on.

[Diah]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

I blindly replaced the power board and main board. No change..

this is yours first post, why don't bring the original main board back and tell us do you have SOUND via HDMI or others input signal ??

[budm]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

So you should then have 12V dc on that side when you switch on.

Very confusing at this point since it does have 12V to the LVDS connector then if that line filter is not bad on the main board. I wonder now if he is having measurement error and we are just chasing tail due to wrong data.
He needs to check the resistance between that inductor against both ends of the SMD fuse on the T-CON to make sure it is connected all the way to the T-CON board.

[JDC]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

this is yours first post, why don't bring the original main board back and tell us do you have SOUND via HDMI or others input signal ??

I hear static (snow) when I turn it on.

[JDC]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

He needs to check the resistance between that inductor against both ends of the SMD fuse on the T-CON to make sure it is connected all the way to the T-CON board.

It would probably be best at this point if you told me exactly how to do that. With the TV unplugged and my meter set to ohms, set one probe on what fuse? The other on what inductor?

[budm]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

Black probe on either end of L1100, red probe on one end of the SMD fuse of the T-CON board one end at a time, it should show <1 Ohm (set meter to 200 Ohm scale).

[JDC]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

Black probe on either end of L1100, red probe on one end of the SMD fuse of the T-CON board one end at a time, it should show <1 Ohm (set meter to 200 Ohm scale).

You mentioned a SMD fuse. Is that the one circled in red in the attached pic? If so, all combinations measure between .5 and .8.

[budm]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

I am surprised that you ask if that is the SMD fuse we need to check the resistance you you have already did the Voltage test on it an it shows as below:

Post #16: F1 fuse on TCON:

ON .014 both sides
OFF 0 both sides

Right now per your measurement you do have continuity from L1100 (checked out to be <1 Ohm) all the way to both ends of the T-CON and you also have 12V at the output of the switched transistor so I do not know why you do not have 12V at the T-CON fuse.

[JDC]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

I am surprised that you ask if that is the SMD fuse we need to check the resistance you you have already did the Voltage test on it an it shows as below:

Post #16: F1 fuse on TCON:

ON .014 both sides
OFF 0 both sides

Right now per your measurement you do have continuity from L1100 (checked out to be <1 Ohm) all the way to both ends of the T-CON and you also have 12V at the output of the switched transistor so I do not know why you do not have 12V at the T-CON fuse.

So far we've been calling it the F1 fuse. Is it also called a SMD fuse?

[budm]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

SMD = Surface Mounted.

[JDC]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

SMD = Surface Mounted.

I understand that but when you refer to the SMD fuse, are you referring to the F1 fuse in this case?

[budm]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

Yes, there is only one fuse (F1) on that T-CON board.

[JDC]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

Yes, there is only one fuse (F1) on that T-CON board.

What is the component that I circled then?

[budm]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

What is the component that I circled then?

That is white component is the SMD fuse which should have 12VDC on it.
So it that the one you measured the Voltage and you get 0VDC?

[dick_barton]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

Courtesy Shopjimmy

[budm]

Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture

Courtesy Shopjimmy

I wonder now as to which FUSE that he tested and got 0VDC reading.