I have a plasma TV model # 50PA6500-UA that when the customer plugs it in, the screen flashes on and off and you can hear a relay on the power supply board continuously clicks on and off. I replaced the relay but the problem persisted. After further testing, I noticed that when the main board is disconnected from the power supply board the problem doesn't occur. Any tests or advice that could lead me to a conclusive board that I should replace would be very much appreciated.