Not an answer as such, but thoght you might be interested in our experience with the same dvd player. We bought an Hitachi PDV313 portable dvd player as a Xmas present for our daughter in 2005, and just over a year later we were unable to play any films or music dvds on it (as usual just out of the limited warranty period!). Despite running through all the troubleshooting tips in the manual, any disc we put in to the player just spins round and round but they won't play so we are assuming there is a problem with the laser. Unfortunately, if you haven't done so already, the best solution is probably to buy a new one if you can. For information, if you are UK based, Argos have a few portable dvd players in their sale at the moment (27.5.2007). I've just bought a Philips PET 706/05 (£79.99 instead of £99.99), although there are no headphones included and its a bit noisy starting up, its got similar features to the hitachi pdv313, same screen size but much less bulky. There are a selection of other players in the sale for a lot less than we paid for the philips (incidentally, in the Argos clearance sale leaflet the Hitachi pdv313 makes an appearance for £79.99! - we personally wouldn't buy another one, but the cheapest we've seen on-line is for £49.99 at www.inest.co.uk). I might try and contact the Hitachi customer services and ask them for some advice on the PDV313 problem, if I get anywhere I'll let you know.
Mrs J Lennon, May 2007