Currently I'm troubleshooting an LG 42PG20 plasma television.
I'm able to confirm that sound works through the three HDMI ports, connected to my PC graphics card.
I hear a "click" when the TV is plugged in, when it is turned on, and again when the TV is turned off. The red standby light on the front of the TV turns blue when "on".
At no point does the panel energize/prime - I have blackout curtains in my room, and cannot see any glow whatsoever coming from the panel while testing.
Initially I assumed
the problem was the Y-SUS board (original part number: EBR50221404), so I replaced the board. The new board was indicated to be compatible per the reputable parts vendor (replacement part number: EBR54740702), but replacing the board unfortunately did not resolve the problem.
The original power board (part number: EAY43533901) provided the following readings on my multimeter:
Definitely out of spec when compared to the voltage listing from the LG repair manual (see first image attachment). The manual I referenced is located at this documentation PDF
I installed a new power board (replacement part number: EAY39333001), also different but confirmed to be compatible. Current voltage readings are:
Despite replacing both the Y-SUS and power boards, there is no change - still have sound, but the panel does not energize/prime.
The images attached display the replacement boards installed in the TV (parts EBR54740702 and EAY39333001).
The main board images are included to show:
I still have the original boards, and can provide pictures of those if necessary.
At this point, I am not sure what to do. Kindly advise as to what I should test next.
I'm able to confirm that sound works through the three HDMI ports, connected to my PC graphics card.
I hear a "click" when the TV is plugged in, when it is turned on, and again when the TV is turned off. The red standby light on the front of the TV turns blue when "on".
At no point does the panel energize/prime - I have blackout curtains in my room, and cannot see any glow whatsoever coming from the panel while testing.
Initially I assumed

The original power board (part number: EAY43533901) provided the following readings on my multimeter:
- Vs: 3.43V
- Vs: 3.43V
- NC: N/A (no pin)
- GND: 0.00V
- GND: 0.00V
- VA: 0.88V
- VA: 0.88V
- GND: 0.00V
- M5V: 0.00V
- M5V: 0.00V
Definitely out of spec when compared to the voltage listing from the LG repair manual (see first image attachment). The manual I referenced is located at this documentation PDF
I installed a new power board (replacement part number: EAY39333001), also different but confirmed to be compatible. Current voltage readings are:
- Vs: 192.6V
- Vs: 192.6V
- NC: N/A (no pin)
- GND: -1.2V
- GND: -1.3V
- VA: 59.6V
- VA: 59.6V
- GND: -0.6V
- M5V: 5.09V
- M5V: 5.09V
Despite replacing both the Y-SUS and power boards, there is no change - still have sound, but the panel does not energize/prime.
The images attached display the replacement boards installed in the TV (parts EBR54740702 and EAY39333001).
The main board images are included to show:
- No power
- Standby
- Powered on (green light on the left turns off after a few seconds)
I still have the original boards, and can provide pictures of those if necessary.
At this point, I am not sure what to do. Kindly advise as to what I should test next.
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