TV wont turn on no standby light

seangosner this”backlight turns on when the main board is disconnected from powersupply “ in general means the issue is the main board but since you already replaced both, I would suggest that you measure the voltage on the connector between your power board and the main board. Let’s see if this turns on since there may be a possibility of a bad P-function board. Take some good pictures of all of your boards and the interconnect wiring between them . that way we can see what you see and try to assist you further.

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