U-band work, explained U, V bands shared mixer in place so there was no failure. Because the UHF tuner IF output signal to the tuner via VHF mixer IF amplifier and then sent to the discharge level.RgDservice manual download site
 RgDservice manual download site
     V band sometimes receive programs sometimes do not receive the program. Not receive the full program on the screen when a nuisance point and adjust the frequency to follow the changes to fine-tune the noise, indicating that high-amp circuit work normal. Emphasis should check the level VHF oscillator circuit.RgDservice manual download site
     Open the high-frequency head plate, find VHF local oscillator tube Q4. After rebooting with a screwdriver to touch the base of Q4, and sometimes can receive images, but one image will disappear again.RgDservice manual download site
     When measured with a multimeter Q4eb no images junction voltage of 0.6V, description Q4 stop vibration.RgDservice manual download site
     Replacing Q4 (2SC2636) fault elimination, indicating poor performance of the original vibrating tube, so that the work of the local oscillator oscillating at a critical state, when the sensor signal is triggered by the body can oscillate moment.RgDservice manual download site