Problem in starting DVD Player

Hello everyone,
I am in a problem in starting a dvd player, the problem is -
When I am starting or play it, the display is OK .. but disc just started for few seconds and then stopped..

I checked the power PCB and found OK ..
Now I want to know - what is the problem ??
And how to solve the issue ?

Usually it's failure of the laser or mechanism, and not worth repairing as new players are so cheap (assuming you could even source the parts?).