Screen is red - Sony FD Trinitron WEGA KV-34HS420 34" TV

Hello

The red colour output section in your TV has some short in it. This section can be located at the picture tube base card, the printed circuit board along with some components are fitted with it. There will be three cathodes, Red, Green and Blue; usually marked as Kr, Kg and Kb. Take the voltages of these pin points at this board. It should be almost the same. In your TVs case, the voltage at the red cathode will be very low now. Look whether transisotrs or Ic is used for video output section in this side. Usually Sony uses transistors. Check the resistor at the collector of red output transistor. If it is open, replace it. If the resistor is OK and still there is no voltage, and the said resistor heats up abnormally, the transistor related to it is leaky [collertor-to- emitter short]. Replace it with same type and number will solve your problem. OK.