Friend, I don't have a scheme for your TV, but if it is from the Philips who use a single traffic, you can't bother anything, this voltage is generated in the main by sub-sources, even if they don't have a load, it doesn't start, the voltages are unstable, what you can do to do (“if this is the case) is to disconnect the main, put a 12 volt bulb as a false charge and inject the points on / off and power dim 3.3 volt with an external source. Before doing this verify no stby voltage is generated at the source through a transistor circuit. Greetings and luck