PlayStation 2 SCPH-70003 disc drive clicking, stuck on reading disc

My PlayStation 2’s DVD drive does not appear to spin up with a certain disc in the drive. It’s Gran Turismo 4. When the disc is in the drive, and the lid shut, all it does it click as it tries to spin the disc (I think). When in the browser, it sits on ‘Reading disc…’ and nothing happens. I’ve only ever encountered this problem on new DVD video discs until now.

Any help would be greatly appreciated.