Initially suspected to be the source of the problem may be the home of another user when using the same 14-inch color TV signal source, each channel are clear, which can eliminate the problem of the signal source, suspected AGC voltage is not in the best condition. Then there is the noise of the machine to the point of interference channels, and then enter the maintenance mode, find CHK2 menu "RFAGC" project, carefully adjust "RFAGC" values ​​until the noise disappears point. Then, they switch to another channel to watch the screen, by repeatedly adjusting "RFAGC" values ​​after troubleshooting.CD9service manual download site