There are mainly three reasons for this fault. The first one is of Damaged Disc. The second one is improper disc loading or disc does not spin inside. The third one is of its laser pickup unit trouble.
To make sure, insert a new disc into the player, and inspect the result. If it does not read this disc, either the disc does not spins inside it, of the laser pickup unit is faulty or dirty.
First, open its tope cover, and place a disc in it. Note
whether it loads the disc properly into and disc starts spins, and the
laser pickup unit tries to track the burned tracks on the CD. You
can see the tracking of laser pickup unit. The unit will go outward end
of the disc first, and will come back to its original starting
position. This process is known as reading. If
disc do not spin inside it, the laser unit can’t track the recordings,
and it will try to read it tow or more times further, and will halt at
last. The display will show No Disc.
If the disc do not spins inside the player, make sure that the sled motor has damaged. The sled motor in one, which locks up the disc we insert into, with a magnetic catcher. This is a stepper motor, and cost not much. But replacing it is a skilled job, as you have to disassemble and reassemble the while mechanism.
Insert a cleaning disc [which can be bought from most of the electronic spare part selling shops at your town]. Play it for atleast 3 times, by taking it ejected from the player, and reinserting. If
the fault is due to dirt accumulated on the lens of the laser pickup
unit, this process the cleaning disc will clean it up, and your player
will be all right now. If it does not help you, make sure that the laser pickup unit is damaged. When replacing this unit, insist on same type and number of laser unit. Never try to use an other number; sometimes it may not work properly.