I have checked voltages are fine, performs all the functions but does not read the discs try to rotate the plate one year or two laps and stop and the message comes out insert a disc. Thanks for your help.

thank you dear joni for your suggestions and I found the fault and is the r3835 of 3.3 ohms that feeds the 10 volts to pin 5 of the servo driver. as you indicated me voltajes and that voltage did not go out by the r. open now it worked very well