This cast judgment but the fault is not part of the circuit due to the aging of CPT red gun. Unplug the CRT tail plate, connected rated filament voltage (6.3V) with a multimeter black pen then the gate, the red pen were measured three cathode resistor values​​, the gun was found in the red 18kΩ, green, and blue guns were less than 1kΩ. After the trial, "Newsletters" 2000 18 "gas stove ignition activated by CPT aging" of the law on the red gun alone carried dozens of activation, measured obtaining the gate, cathode resistor value has been reduced to 1.1kΩ, insert Watch the back transom boot image color normally, but ten minutes later they were blue in the image fault condition. Off the red gun retest the gate, cathode resistor value has promoted 50kΩ. Then I switch to another activation method: filament voltage plus 10V, and also between the gate and cathode of the red gun plus 6V (gate positive and negative Yin) voltage, about 15 minutes after the resumption rated filament voltage, measured red gun gate, cathode resistor value and green, blue gun consistent, plug it back in to watch the boot tailgate, color image back to normal.XxSservice manual download site