Panasonic TC - 2997 color TV turn blue and flyback line fault. Once the received signal (both TV and AV status are so) is automatically converted to black screen and no character display. But there's a light at the end of the shutdown instantaneous smell. qLDservice manual download site
 qLDservice manual download site
According to the fault phenomena analysis, as when a signal is input video channel. Small signal processing such as video/colour/scanning measurement integrated block M5234021, 22, 23 feet (R, G, B signals output) are around 2.5 V voltage (3.4 V) normally, the replacement after the problem is still, so if the CPU is not normal work? Press the panel TV/AV key, at the same time, measured the CPU (M37220M3) 30 feet (AV/TV conversion control) of the output level is high and low, that means the CPU working conditions (power, crystals, reset, button scanning) basic normal, and in the press TV/AV key, CPU 27 feet (SCL), 38 feet (SDA) voltage is 4.8 V, this shows the CPU work basic normal, there could be a failure condition is not satisfied. Have the characters, according to one of the necessary conditions to yukon line, field flyback pulse to locate, so whether the two pulse has reached the CPU? First CPU 1 foot (h. SYNC) waveform measurement, indeed as expected no conduct flyback pulse signal waveform, find out is the line flyback pulse transmission circuit of clamp diode VD801 (8.2 V) breakdown, the fault disappear after replacement.qLDservice manual download site