LDW-851S failing to read CDs



It seems my LDW-851S@832S (VS0G, Omnipatched) has developed a fault. When I insert a CD, it does a few spinup-buzz-spindown cycles, then gives up. After reinserting the disc a few times, the drive usually picks up the disc OK. DVDs still seem to read OK, without the need for retrying. Needless to say, this is rather annoying.
Does anyone have any ideas why this might be happening? It’s well out of warranty anyway due to me reseating the tray on its runners after catching my jacket on it a few weeks ago. As far as I can remember, it’s always done this to some degree, but it’s been getting a lot worse recently.

Is it worth pulling the drive apart and cleaning the laser lens?