"No Disc" errors are generally caused by an internal build-up of debris such as hair, lint, and dust, and in some cases may be due to a failing laser mechanism.

If you are able to hear the player attempting to read a disc once you insert it, but the end result is still a "No Disc" error, you may be able to resolve the issue in one of two ways.

1. 1. Eject the tray and attempt to clear out any debris or obstructions with compressed air.
   
2. 2. Use a laser lens cleaner, such as Memorex's OptiDisc, to remove any dust or other obstructions from the lens itself.
3. 
   

If the issue persists after those two steps, contact OPPO Customer Support to set up an RMA.

If after inserting a disc you immediately get a "No Disc" error, and it does not sound as though the player is attempting to read the disc at all, then attempting to use compressed air or a laser lens cleaner will likely have no affect, and the player will need to be serviced.