Observation on the boot tube filament light, measuring three gun cathode voltage up to 190V, the video is in off state, measuring amplifier integrated circuit block N150 7, 8, 9 feet and 5 feet, the voltage is 190V, voltage is 0V, check the bias resistor, r1519 (220K) open, replacement, boot, 5 feet electric pressure rise to the normal 1.3V, TV image appears, repair.iuaservice manual download site