If you thought the dvd disc player you just purchased was a pup or you are having pixelation/picture freeze with your discs,dont despair.  Apart from the obvious eggs/butter/mud etc.on the surface of the disc in all probability the mechanism of the player just needs maintenance. The laser carriage slides on two rods,these rods become dry/sticky and inhibit the travel of the laser.To effect a cure you need to open the casing AFTER UNPLUGGING/DISCONNECTING THE PLAYER.if that worries you do not proceed. If you turn into toast you unplugged the wrong thing. Get the machine on the bench,just to make sure it is not wired up! Two or three screws at the back of the player(on most models) hold the cover on, which should have a sign telling you about the dangerous laser inside.Since you UNPLUGGED the machine the laser wont work. The two carriage rods will be seen after carefully removing the cover. The laser carriage slides on the rods,give them a wipe with kitchem roll if dirty.To lubricate the rods I use graphite powder,`sparingly`.Graphite powder is the stuff used as pencil lead, scrape a pencil lead with a sharp blade onto a plate or buy some graphite powder.Someone on ebay probably does! Do not use graphite grease or any grease.Do not spray with lubricant or liquids.And dont fiddle with anything else inside the machine.

Use a DRY cotton bud dipped in the DRY graphite powder and with care dab/stroke the carriage guide rods.Making sure you dont use too much and get the machine looking like a pencil factory floor inside,on a friday night.Slide the carriage a couple of times and thats it.Put the case back on.BEFORE plugging back in .No warranty implied or given.You may have a bigger problem with your machine, if so take it to a qualified service engineer.                                                                                                                 The above is for the owners of older dvd players, if yours is under warranty do not remove the cover as this will most probably void any warranty,contact the vendor.Think ELECTRICAL SAFETY FIRST!

The information above has worked on the machines i have had and with lasting results. But please if you have any doubt of your ability.TAKE THE MACHINE TO A QUALIFIED ENGINEER.  GOOD LUCK.