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

[JDC]

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

Those are only half of the pin outs. There are 18 of them in total. We need all of them plus the pin out name!
However... there is no voltage going to the Tcon. no voltage there, no pic. Maybe disconnect the tcon and see if the voltage re appears on the connector.

ON

-.009
12.13
12.13
-.01
24.48
-.011
3.51
3.51
3.104

OFF

0
.009
.009
0
.006
0
3.55
3.55
0

Attached is a diagram for the connection from the power board to the main board. It says:

P201

GND GND
12V N.C.
12V 12V
GND GND
24V 24V
GND GND
3.5V PD1M2
3.5V PD1M1
PWR-ON DRV-ON

[JDC]

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

Edit
Please can you provide some sharp picture of your main board which would be of help.

Is this better?

[JDC]

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

from yours T-CON photo it show to me the left ribbon cable not correct sitting at the panel socket., take them both out and check the Gold pins of them, then reset them correct, as they labeled with hand writing they seem had story.

Reseated, nothing out of the ordinary I could see, still no change. Thanks anyways.

[charis]

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

If your backlight start and the panel stay black is T con problem.
Usualy this symptoms happen to samsung tv but the sound works.
Try to heat the main processor and see if you have picture untill he cools .
Also check the regulators near processor specially the 5v and VCC.
If nothing happen your tcon is faulty.
To test Tcon jump 12v from SMPS to the Tcon fuse.Disconect the LVDS cables Jump VCC 3.3v to the LVDS(CN1) connector ground pin.Aply ac to power supply, patterns of White, Red, Blue, Green
should appear on the screen.Voltages can be read at the ribbon connector or at test locations on the board (typical 16.74V, 3.3V, -5V and 28V)

[CapLeaker]

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

ON

-.009
12.13
12.13
-.01
24.48
-.011
3.51
3.51
3.104

OFF

0
.009
.009
0
.006
0
3.55
3.55
0

Attached is a diagram for the connection from the power board to the main board. It says:

P201

GND GND
12V N.C.
12V 12V
GND GND
24V 24V
GND GND
3.5V PD1M2
3.5V PD1M1
PWR-ON DRV-ON

O.k., you measured GND, 12V, 12V GND, 24V, GND, 3.5V, 3.5V and PWR-ON.
Where are the GND, NC, 12V, GND, 24V,GND, PDIM2, PDIM1 and DRV-ON measurements?

[JDC]

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

O.k., you measured GND, 12V, 12V GND, 24V, GND, 3.5V, 3.5V and PWR-ON.
Where are the GND, NC, 12V, GND, 24V,GND, PDIM2, PDIM1 and DRV-ON measurements?

Yikes! I see what I did wrong now. I'll get back to you. Thank you for being patient.

[dick_barton]

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

Did you manage to follow the wiring back from the Tcon fuse back to any component on the main board. You said earlier that the 12V on the Tcon fuse was missing?

[JDC]

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

Did you manage to follow the wiring back from the Tcon fuse back to any component on the main board. You said earlier that the 12V on the Tcon fuse was missing?

I haven't yet, no. You are referring to the F1 fuse on the TCON?

[CapLeaker]

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

yes, he is.

[JDC]

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

yes, he is.

???

[JDC]

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

While the TV is on, placing the neg. probe on either side of TCON's F1 fuse, and the pos. probe on the very first pin (on the left) on the still connected TCON cable, I get a reading a 12.13 VDC.

[JDC]

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

If your backlight start and the panel stay black is T con problem.
Usualy this symptoms happen to samsung tv but the sound works.
Try to heat the main processor and see if you have picture untill he cools .
Also check the regulators near processor specially the 5v and VCC.
If nothing happen your tcon is faulty.
To test Tcon jump 12v from SMPS to the Tcon fuse.Disconect the LVDS cables Jump VCC 3.3v to the LVDS(CN1) connector ground pin.Aply ac to power supply, patterns of White, Red, Blue, Green
should appear on the screen.Voltages can be read at the ribbon connector or at test locations on the board (typical 16.74V, 3.3V, -5V and 28V)

This is good information. I'm not sure if I'm brave enough to try it yet. Thanks!

[budm]

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

LG EBT62421329 (EAX65049105(1.1)) Main Board for 47LN5200-UB
http://www.shopjimmy.com/lg-ebt62421...7ln5200-ub.htm

Is this your main board?
Check the resistance between BOTH ENDS the inductor L1100 to the T-CON fuse to make sure it has <1 Ohm resistance.
Check the DCV (ref. to chassis GND) of all 3 legs of Q409 when TV is OFF and when TV is turned ON.
Pictures provided by shojimmy.

"While the TV is on, placing the neg. probe on either side of TCON's F1 fuse, and the pos. probe on the very first pin (on the left) on the still connected TCON cable, I get a reading a 12.13 VDC."
BTW, the readings should be done with Black probe to the chassis GND, not on the parts.
Fuse shows <1 Ohm for sure?

[JDC]

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

O.k., you measured GND, 12V, 12V GND, 24V, GND, 3.5V, 3.5V and PWR-ON.
Where are the GND, NC, 12V, GND, 24V,GND, PDIM2, PDIM1 and DRV-ON measurements?

While ON:

GND: 0 GND: 0
12V: 12.13 N.C.
12V: 12.13 12V: 12.13
GND: 0 GND: 0
24V: 24.47 24V: 24.47
GND:0 GND: 0
3.5V: 3.52 PD1M2: -.001
3.5V:.52 PD1M1:.984
PWR-ON:3.111 DRV-ON:1.010

[JDC]

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

LG EBT62421329 (EAX65049105(1.1)) Main Board for 47LN5200-UB
http://www.shopjimmy.com/lg-ebt62421...7ln5200-ub.htm

Is this your main board?

Looks to be it.

Check the resistance between BOTH ENDS the inductor L1100 to the T-CON fuse to make sure it has <1 Ohm resistance.

See attached. Are you referring to the circled component? If so, it measures -14.44 with every combination of probe placements (wanted to be thorough). Not sure I did this right.

Check the DCV (ref. to chassis GND) of all 3 legs of Q409 when TV is OFF and when TV is turned ON.

Are you referring to IC409 on the main board? If so:

OFF
1.840 0
_________

.023

ON
3.42 0
________

3.74

"While the TV is on, placing the neg. probe on either side of TCON's F1 fuse, and the pos. probe on the very first pin (on the left) on the still connected TCON cable, I get a reading a 12.13 VDC."
BTW, the readings should be done with Black probe to the chassis GND, not on the parts.
Fuse shows <1 Ohm for sure?

ON and OFF shows 00.3

[budm]

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

How about Q409 that have marked for you to test pin 1~3?
https://www.badcaps.net/forum/attach...0&d=1461687797

[budm]

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

BTW: 'Quote:
Check the resistance between BOTH ENDS the inductor L1100 to the T-CON fuse to make sure it has <1 Ohm resistance.
See attached. Are you referring to the circled component? If so, it measures -14.44 with every combination of probe placements (wanted to be thorough). Not sure I did this right.

Do you know how to use the meter? -14.44 is what? Volt or Ohms, and are you measuring the Ohm when TV is plugged into the outlets? Is that the way you also check the fuse on the T-CON?
No power should be applied to the TV when makes resistance checking.

[JDC]

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

how about q409 that have marked for you to test pin 1~3?
https://www.badcaps.net/forum/attach...0&d=1461687797

off

.005 .006
0

on

12.11 1.784
12.11

[budm]

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 = ???

[JDC]

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

Do you know how to use the meter? -14.44 is what? Volt or Ohms, and are you measuring the Ohm when TV is plugged into the outlets? Is that the way you also check the fuse on the T-CON?
No power should be applied to the TV when makes resistance checking.

So when checking resistance, does that mean unplug the TV or it being in an OFF state is okay?