Observation about ten minutes after the machine for the first time boot image gradually appear level "hair" phenomenon, after about half an hour of image details cannot distinguish, its shape like video replay after recording many times, at the same time whole image with a black shadow interference. Brightness down after failure occurs. Shut down for a moment after the boot image is normal, but the fault quickly. From boot failure occurs to the length of time according to the temperature of the machine, the higher the temperature the faster failure occurs. aX2service manual download site
Analysis of reasoning: from the fault phenomena analysis, it is a fault related to the temperature. Failure occurs after the image detail can't distinguish that loss of high frequency component in the video signal. Due to image synchronization state is always good, so check the emphasis should be placed on the video part of the circuit. aX2service manual download site
 aX2service manual download site
 aX2service manual download site
General TV video part of the circuit is relatively simple, from circuit output video signal is put into the decoding IC after color decoding and luminance signal amplifier, the output level at the end of the direct drive tube cathode to inspect. But the machine USES panasonic M18M machine, the machine function, and USES a variety of video processing technology, as a result, the video signal process of twists and turns, very complicated. According to the machine circuit diagram of the PAL signal process as shown in the appended drawings. aX2service manual download site
Into the circuit IC101 (M52760SP) of the output video signal by IC201 (M52317SP) after selecting TV system, sent to the AV/TV conversion circuit IC3001 (AN5858K), IC3001 choose the required video signal and output by {} 21 feet, sent to good Y/C separation circuit separation degree of signal (C) and luminance (Y), and back IC3001 20} {and} {19 feet, by IC3001 17} {the output signal Y feet, output signal C {} to 15 feet. Y in turn into the image signal of artificial intelligence (A1), horizontal sharpness enhancement circuit for processing, and then sent to the chroma processing circuit IC601 (TA1215AN).

 3    1 2 3 Next Last