Samsung SD-616T

Sadly something dire seems to have happened to my Samsung DVD player. The swine won’t read any dvds any more for some unknown reason. When a dvd is entered, the read light’ll flash for a bit and stop, the nothing. It’ll play data and audio cds fine but not dvd. I haven’t altered the firmware or installed anything that might mess it up. The only thing I can think of is a hardware problem or a dirty lens ? Any ideas anyone ?

Many thanks