Open the cover to check, add VCD dish, found the spindle does not turn, exit disk head focus tracing observation, action, also have a laser. Analysis of the main shaft does not rotate the scope of fault in: laser head RF signal amplification, detection, DSP, drive, power supply etc.. First, measured with a multimeter FOK signal input OM52842 pin is high (if a boot on the low level, the spindle is also not turn) is normal, then try playing a normal laser head substitution, fault phenomenon remains unchanged, the fault is not bald cause. Remove the servo plate boot, with a multimeter measuring DC voltage blocking RF signal amplification integrated block TDA1300 feet voltage, found that part of the foot error, in which 1 ~ 5, {19} ~ {24} feet are DC voltage (normally undetectable), estimation of the integrated block has been bad, with a new integrated block replacement, troubleshooting. As the TDA1300 market is hard to find, also can use TDA1302 direct substitution. TDA1300 of normal and abnormal data compared to see the left shown in the table below.Qrbservice manual download site