"Two main boards exhibit same behavior. A third main board would sometimes go into menu and even display PIP video and sound in menu on input selection screen. When input selected (HDMI) only audio came through, no display on full screen, this board took software update."
It looks like you do have main board problem, especially not all of them acting the same way.
"LED Outputs are both 64.75 steady instead of 66 volts." BL-ON is OK otherwise you will not get the LED Voltage.
BTW, on the LED connector, what are the Voltages on each one of the pin with ref. to GND? The 64.5V is ref. to GND?
"LED Outputs are both 64.75 steady instead of 66 volts." BL-ON is OK otherwise you will not get the LED Voltage.
BTW, on the LED connector, what are the Voltages on each one of the pin with ref. to GND? The 64.5V is ref. to GND?
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Yes Sir Bud. 64.75V to chassis. I can check them to the corresponding GND terminal on the same connector. Will do so and post.
INVON is 1.84V and I do get backlight.
So far both mains supposedly came from sets damaged in shipping yet they claim they are tested good. If they power up a set with a cracked panel, can it damage the main board?
My source for main board CPU replacement says no parts are available to repair the original main board.
Thanks to all for your assistance!! I appreciate it!
In answer to your question Bud, if I test LED+ to LED- I get 63.95 volts. If I check LED+ to PFC Main Cap -, I get 112 volts.
I am convinced that the CPU on this main board has only base rudimentary firmware on it or has a physical problem.. If I plug a USB drive into it, it will read the drive, but will not ask me if I want to update. If I boot cold with USB drive in, it will read it, but still not ask me if I want to update.
"In answer to your question Bud, if I test LED+ to LED- I get 63.95 volts. If I check LED+ to PFC Main Cap -, I get 112 volts."
When testing the LED connector Voltgaes you will test the LED connector pins against cold/chassis GND.
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