Boot after first check the power supply part, found PF4, PF3 two insurance tube has fusing, change after two insurance tube, electricity insurance tube fuse again, short-circuit phenomenon existing in the load circuit. dp9service manual download site
The machine after PBD1 rectifier transformer secondary voltage output to the + 12 v power supply via PCW6 plugin supply motherboard, short-circuit point to determine, disconnect PCW6 on the power of the power cord, measure voltage return to normal after the power supply, motherboard have short circuit phenomenon. Along the line inspection, found that the road is the main supply voltage motor driver circuit SIC4, SIC5 two LA6510. Check SIC5, found its internal damage, after replacement, fault elimination.dp9service manual download site