One Samsung DVD player after 25min of playing picture is freezing (stuck), sometimes picture is played intermittently with broken sound. I saw optical block dancing backward and forward when this trouble starts. Replaced spindle motor problem was same.
This sounds like the system is overheating, check if the fan is working if it has any and also check if you have capacitors which are faulty, use an ESR meter to test all capacitors on the power supply board.
Any sign of bulged top on capacitor should be replaced directly; this can help you to pick faulty capacitors especially if you don’t have an ESR meter.
Another problem is how to adjust height of disk holder on top of the spindle motor.
There is no standard height recommended...what is not recommended is setting the height extremely low or too high.
LOW HEIGHT: Let me gave an example of how you can have a low height…this occurs mostly by the user who by mistake insert two disc at ago and this will cause the spindle platter to move down to accommodate extra disc. Usually when this occurs one can notice that when you open the dvd cover and try to rotate the disc with the hand, the disc will be touching the disc bed instead of only sitting on the platter only.
HIGH HEIGHT: on the other hand high height is caused by the technician especially after replacing the spindle motor with a new one and fail to set the height like before. This can be avoided by the technician himself/herself noting the height of the previous motor. For me I use a small screwdriver body and insert it between the platter and the motor. So on the new motor I just insert the screw driver and press down the platter until it touches the screw driver.
Thanks in advance,
buyer of your DVD player repair ebook.