Why does it keep saying unrecognised discs

Make sure to check the following things:

• No major scratches on the discs;
• The disk actually starts spinning;
  • You should be able to hear it spin when you're close to your console.
• There are no stuck discs inside
  • To remove a stuck disc, either hold the eject button until it has been removed, or open the HDD cover by sliding it off, and look on the left side of the console. Between the vent holes should be a small screw that allows you to manually eject a disc.

If none of these apply, it is quite likely that the lens is dirty. Buy a lens cleaning disc, or for a higher success rate, open your console and clean the lens with a Qtip and some isopropyl alcohol.

If it still doesn't work, the Blu-ray drive is mostlikely broken and needs replacement.

Good luck!