Observe the machine just figure when the phone is switched on, normal, sometimes watch a minute or two, sometimes half an hour, began to appear in the image noise points. Noise increases with the viewing time point more and more, the last image disappear, in full screen noise points.
 
According to the fault phenomena analysis, focusing on high frequency voltage of the head of BM, BT, AGE. Found in addition to the AGC voltage unstable, other test point voltage are normal.
 
Test images and sound amplifying circuit IC101 (AN5179NK)} {19 feet power supply voltage of 5 v is normal, and {} to 18 feet AFC is 8 v and unstable power supply voltage, normal voltage should be 12 v. This puts plate for double-sided circuit boards, linear complexity. After careful examination, found lC101} {19 feet power filtering electrolytic capacitor C167 (470 mu F / 6.3 V) the following circuit board have a layer of black holes conductive, reality check for C167 caused by leakage. With a model 500 multimeter Rxlk measuring its conductive hole resistance, normal should be 0 Ω, measured at about 8 k Ω fluctuations. With wires connected conductive hole, and replace C167 commissioning, troubleshooting.