Panasonic PansenIC XV - A300 DVD, broadcast images, audio, after a time, suddenly disappeared, no display screen, at this time go disc is still normal. To turn it off for several hours after the boot. Images, with green, back to normal again, failure to reproduce over a period of time.
 
Doubt a decoding circuit element thermal stability is poor. It USES ES3204 decoder board, + 5 v power supply is normal and stable. Failure occurs when the touch ES3204 each manifold blocks such as no abnormal temperature rise. Many times on the maintenance of commissioning. Find fault in time and has great randomness, and sometimes no image the screen is red, green, sometimes sometimes dark, sometimes gray. Variable. Visual inspection on decoding board each component solder joints virtual welding. Watch this ROM storage blocks not welded on the circuit board directly, but through the socket is connected to a circuit, the storage blocks, there are more than 30 pin suspected of poor contact is the largest. Carefully remove the ROM storage blocks, with blades scrape all pins reinsert after commissioning, fault is still.
 
 
Helpless, suddenly remind of color TV remote control met outdated maintenance when the intermittent fault, fault source is mostly crystals, can be normal after the change. The machine malfunction can be caused by crystals? Check the machine USES the crystal Zhan, model parameters for LDX14.31818 MHz, with models for PRE14.31818 MHz crystal vibration after substitution, over and over again for a long time of commissioning, images, audio, audio and video output has been normal.
 
But using radio frequency socket signal input but no color TV set. Determine the rf output video output normal and abnormal, found no problem. Check the radio frequency modulation circuit asks the user to know to send a disk drive before rf output color has been normal. Because only when maintenance replacement crystals, doubt the new change of the crystal. The performance of vibration from same below models a ES3204 decoding board and remove crystals LDX14.31818 MHz after replacement, regardless of the video, rf output, color images were normal.
 
Summary: 1, the damage of crystals can cause some unexpected intermittent failures. Sometimes resembling a poor contact; 2, crystals have a vital role in the digital circuit. Its substitution not as easy as some components, may cause the image quality is a little difference color aberration.