According to the phenomenon of failure, with the repair experience to determine the number of bald aging. Try to trim the micro potentiometer on the optical pickup module, increase the laser output power of the laser, and the failure phenomenon is still. Sony KSM213CCM type the machine head assembly, with the same type head assembly KSM213VCM type direct substitution of commissioning, fault phenomenon to ease a lot, play process, image stops, the mosaic phenomenon decreased a lot, but the newer non genuine disc head also detected signal and tracking coil head assembly consecutively issued "squeak" sound very loud and cannot be played. Conclude that the problem of movement PCB30B circuit board. The circuit board connector and connecting cable is more, some very short, to be very careful when repairing. Unplug the connector on the circuit board, flip, carefully observed with a magnifying glass solder on the circuit board is smooth, no Xuhan phenomenon. Re installed circuit board test machine, all the dishes are not playing, which is really strange. After the electric power, after careful observation, put into the plate, found that the plate is not rotating (spindle motor not to). No plate observation, found that the optical lens has the upper and lower focus action two times (normal time should be the focus of the action), and there is no laser shot on the objective lens, the screen shows the DISC NO". Check back to PCB30B circuit board component solder joints and connectors, confirm that there are no problems after the test machine, bald or only twice focusing action, objective nor normal laser spot. The CPU control part of the machine is made up of CXP50116. The CPU {63} (ON LD) is used to measure the voltage of the CXP50116, and the output of the laser light is illuminated, which indicates that the {63} is normal. Then check the Q001 (2SA952) pin without voltage. After shutdown, the road resistance values in each pole road rough measurement Q001 is the normal range, high times and then amplifying mirror under the glare of the scrutiny of the Q001 each foot solder joints, find Q001 feet each solder joint surface although light, but is not easy to detect the slightest crack, so the Q001 the three legs of the welding machine, head lens focusing action returned to normal and laser injection, into the dishes can play the. In normal play, the pole voltage value of Q001 is: emitter 4.5V, base 3.8V, collector 1.7V (collector is laser light output pin).

But the non genuine choose disc and head assembly of the tracking coils has been issued a loud "squeak" sound detection and remained undetectable in the directory, the disc cannot be played. Most other dishes can be played. The disc image quality is a bit poor when a pause and mosaic phenomenon. Why this difference correction ability machine? Analysis of reasons: the imbalance of power supply voltage is too low or instability, weak RF signal, tracking servo system. Measuring the power supply voltage normal. Shaved head is a new genuine goods, there should be no problem. The RF amplifier and servo control process for the cxa1782bq. In PCB30B across the board without an adjustable potentiometer. First check the servo circuit board cxa1782bq the foot of peripheral resistance capacitance element, did not find the problem, the tracking servo processing parts, such as the left shown in the figure.

Figure R06 decided tracking amplifier gain, R07, R10 decided the gain of the sliding drive and change its resistance to gain variations. Try to R07 (18K) and R10 (82k) on the position after the test machine, the fault phenomenon disappeared. That non - genuine inferior dish can also be detected in the directory and play a normal! Other disc playing in error correcting capability to return to normal, image basically eliminates the pause and mosaic phenomenon, thus the machine fault fix all of them.

Summary: the machine is a machine three fault. Is baldheaded aging; second is Q001 actual solder joints are weld; three is tracking servo gain variation, resulting in the error correction capability. The machine after the repair, I will put the original head assembly, the fault as mentioned before, to verify the head does not use aging. Fault 2 the phenomenon actually has been included in the beginning of the fault phenomenon, but there is no discernible in the repair process of turning the circuit board fault phenomenon more obvious bale. Of fault, I estimate is the internal performance of servo tracking cxa1782bq change due to poor, swap second resistance change tracking gain. Results the recovery of the error correction capability.