Hello, I have an LG 50PA6500 Plasma TV, purchased new on June of 2012.
I am willing to climb tall mountains to get this plasma TV fixed since the picture on this TV has been absolutely gorgeous and this is a 1080p (not a 720p).
I have an old-school Tektronics dual trace 60Mhz scope (if it comes down to that.)
When I connect the power cord to 120 VAC I get two relay clicks from a black relay RL103 located near the bottom edge of the PSU. When I turn the TV on (either with remote or hard power button) I get one relay click from the same relay.
Also, when I turn it on it gives two red power LED blinks and then nothing. No picture, no sound, no ability to set/adjust settings or select inputs since the screen is dark.
This TV had a problem when it was around 6 months old. LG sent a mobile service van to fix it and they changed a board. This TV has a power PC board that is “refurbished,” so I am thinking the LG guys replaced the power board at that time.
Without disconnecting anything from the PSU (PN=EAY62609701) I am getting the following voltages from the PSU:
VS = 200-206 / actual = 204,
VA = 55 / actual = 54.9,
M5V = 5.2 / actual = 5.16.
From another PSU board connector with thinner wires:
17 / actual = 17.24,
5.2 / Actual = 5.20,
ERROR CORRECTING 5.2 / actual = 5.20,
STBY / actual = 5.20,
RL_ ON (AC_DET) / actual = 2.54,
M_ON (AUTO GND) / actual = 3.29.
When I turn the TV on, the MAIN (input) board (PN=EAX64280504) has a solid LD500 RED LED.
The CONTROL (PN=EAX64290701) has D101 GREEN LED with LONG-SHORT (pause) LONG-SHORT. These four blinks (including the middle pause) is then repeated as a pattern.
I have removed the Y-SUS, Z-SUS, and PSU boards. Gave these three boards an inspection for cold solder joints. “Push tested” with my finger looking for loose solder joints. Gave all diodes an in-circuit front-to -back ratio check. (Diode D256 on the Y-SUS tested shorted in-circuit, but out of circuit it tested ok; there is a 2.2 ohm resistor in parallel with this diode.) Tested all power MOSFETs on these three boards for self-shorts or shorts to ground. Between these three boards there are a total of four fuses and they are all ok.
Visually inspected all visible electrolytic caps in this TV for bulging or leakage, they all look ok.
Visually inspected all visible resistors in this TV for any sign of overheating, they all look ok.
Visually inspected all visible power MOSFETs in this TV for any signs of overheating, they all look ok.
There are voltage potentiometers on the Z-SUS and Y-SUS boards, but I do not know where these test points are located nor what values of voltages to look for. NOTE: I HAVE NOT MESSED WITH THESE VOLTAGE POTENTIOMETERS AT ALL!
I have the CONTROL ext_auto_gen test through-points bridged with solder and wire and the ribbon from the MAIN to CONTROL disconnected at the MAIN, but all of the symptoms are exactly the same: two red power LED blinks, same repeating pattern with the CONTROL D101 green LED. (However, LD500 RED LED on the MAIN has no activity.)
Thank you, and lets keep these PLASMA TV sets alive!
I am willing to climb tall mountains to get this plasma TV fixed since the picture on this TV has been absolutely gorgeous and this is a 1080p (not a 720p).
I have an old-school Tektronics dual trace 60Mhz scope (if it comes down to that.)
When I connect the power cord to 120 VAC I get two relay clicks from a black relay RL103 located near the bottom edge of the PSU. When I turn the TV on (either with remote or hard power button) I get one relay click from the same relay.
Also, when I turn it on it gives two red power LED blinks and then nothing. No picture, no sound, no ability to set/adjust settings or select inputs since the screen is dark.
This TV had a problem when it was around 6 months old. LG sent a mobile service van to fix it and they changed a board. This TV has a power PC board that is “refurbished,” so I am thinking the LG guys replaced the power board at that time.
Without disconnecting anything from the PSU (PN=EAY62609701) I am getting the following voltages from the PSU:
VS = 200-206 / actual = 204,
VA = 55 / actual = 54.9,
M5V = 5.2 / actual = 5.16.
From another PSU board connector with thinner wires:
17 / actual = 17.24,
5.2 / Actual = 5.20,
ERROR CORRECTING 5.2 / actual = 5.20,
STBY / actual = 5.20,
RL_ ON (AC_DET) / actual = 2.54,
M_ON (AUTO GND) / actual = 3.29.
When I turn the TV on, the MAIN (input) board (PN=EAX64280504) has a solid LD500 RED LED.
The CONTROL (PN=EAX64290701) has D101 GREEN LED with LONG-SHORT (pause) LONG-SHORT. These four blinks (including the middle pause) is then repeated as a pattern.
I have removed the Y-SUS, Z-SUS, and PSU boards. Gave these three boards an inspection for cold solder joints. “Push tested” with my finger looking for loose solder joints. Gave all diodes an in-circuit front-to -back ratio check. (Diode D256 on the Y-SUS tested shorted in-circuit, but out of circuit it tested ok; there is a 2.2 ohm resistor in parallel with this diode.) Tested all power MOSFETs on these three boards for self-shorts or shorts to ground. Between these three boards there are a total of four fuses and they are all ok.
Visually inspected all visible electrolytic caps in this TV for bulging or leakage, they all look ok.
Visually inspected all visible resistors in this TV for any sign of overheating, they all look ok.
Visually inspected all visible power MOSFETs in this TV for any signs of overheating, they all look ok.
There are voltage potentiometers on the Z-SUS and Y-SUS boards, but I do not know where these test points are located nor what values of voltages to look for. NOTE: I HAVE NOT MESSED WITH THESE VOLTAGE POTENTIOMETERS AT ALL!
I have the CONTROL ext_auto_gen test through-points bridged with solder and wire and the ribbon from the MAIN to CONTROL disconnected at the MAIN, but all of the symptoms are exactly the same: two red power LED blinks, same repeating pattern with the CONTROL D101 green LED. (However, LD500 RED LED on the MAIN has no activity.)
Thank you, and lets keep these PLASMA TV sets alive!
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