Open the machine cover, found within the laser in the instant power supply is connected to slip back into action, this shows that the feed servo is normal, also shows that the laser with a laser beam, with tracking error signal, thus further conclude that the digital servo circuit, digital signal processing (DSP) circuit is normal, the fault range narrowed to focus/tracking drive circuit. 9PLservice manual download site
The pattern in the heart is a typical philips CDM12 machine heart. Key test U3 (TDA7073A) driving integrated circuit each foot voltage and resistance in the road, found that focus on output {13}, {16} feet voltage 0.6 V (normal is 6 V), remove the focus coil plug, measured their resistance, positive and negative results {16} feet to the ground resistance is 1.3 k Ω (normal and reverse resistance Ω Ω 8.5 k and 8.5 k, respectively), determine drive integrated circuit has short circuit damage. To change new, the machine can normal play. Points out, by the way: when the driver circuit performance deteriorate, will lower the driving force to focus the search up and down shaking range (i.e., adjustable amplitude) is not enough.9PLservice manual download site