Facing TV Problems? Ask a TV Technician.
Hello, and sorry you're having problems. You're only getting 5 volts because your Mainboard is not producing the turn on command to the power supply. This is a common mistake people make when repairing these sets. 5 volts feeds your Mainboard and your Mainboard produces the turn on command that allows the power supply to engage and power up the set. You need to replace your Mainboard- which is the AV Input board. Your power supplies have all been fine. If you need help locating the Mainboard then pull the part number off of the board in your set, or postback with the model number off of the back of the TV and I can dig deeper to help you.
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