Remove this machine machine cover inspection, found that focus, tracking movements are normal, but without laser. The machine controlled by microprocessor IC6031 system (MN1020819N2D) signal automatic focusing, tracking, through 12 c bus interface into the servo control circuit, the focus, tracking drive circuit in the process of search, laser diode driver circuit output voltage at the same time, the light laser diode and the machine into the normal search program. At this time if the machine diskless, check out automatically back to stand by in situ laser components. YzTservice manual download site
 YzTservice manual download site
No laser, laser head should check whether there is any work on the laser voltage. Make laser components in the search state, measuring the line 9, found no voltage, explain the reason for the machine fault is not sent to the laser light of laser diode driver voltage component. YzTservice manual download site
 YzTservice manual download site
The driving voltage from IC5001 output low level, (5) the foot to the triode Q5001, make its conduction, its c and output voltage to light laser diode (see chart). Measuring Q5001 c is 0.16 V (normal is about 4.9 V), check its peripheral component R5003, R5004, R5005, C5009 all normal, doubt Q5001 defective, the welding inspection, found that Q5001 e - c has extremely close to the open circuit state. Replace Q5001 after commissioning, troubleshooting.YzTservice manual download site