After booting the first of all check the power supply section, found two PF4, PF3, fuse has blown, after replacing two fuse, power fuse fuse again, indicating there is a short circuit in the load circuit.
The transformer secondary voltage after PBD1 rectifier output ± 12V power supply motherboard via the PCW6 plugin, in order to find fault, disconnect the power PCW6 the power cord, power voltage to return to normal, description the Board has a short circuit. Along the ray, we found that the main supply voltage motor drive circuit SIC4, SIC5 two LA6510. Check SIC5, the internal damage is found, replace, and trouble shooting.