Ironically, "this person" was exactly correct. The DVD/Surround combinations are notorious for getting a lot warmer than a stand-alone DVD player. The added heat from processing and amplifying 5.1 surround sound will actually cause what little grease was applied at the factory to dry up and cause the laser head to skip, or even freeze up. Playing the scratched disk would have caused it to get even hotter than usual and the laser head assembly would have had to try even harder to read the disk. That would have likely caused it to just freeze up.
Don't worry, should be a simple fix. Hope you are brave enough to try some surgery on your player!
I have never disassembled a Zenith player, but I would imagine it's similar to the Sharps, Sonys, and Panasonics I've worked on.
Begin by ejecting the disk tray. Without turning the power off, just unplug the player from the wall so that the tray is stuck out. (don't worry, won't hurt a thing)
Next, remove the cover. Probably two screws on either side and one or two at the top on the back of the player.
Notice where the disc tray usually inserts, and locate a little metal cover with a round plastic piece in the center. Remove all screws holding it in place. You should now see the lens assembly and two metal tracks that it moves back and forth on. Using a q-tip, apply a generous amount of grease (use something like bicycle lubricant, or any high-heat lithium based grease) to both metal tracks.
Now, gently grab the Laser assembly (without touching the lens) and slowly glide it back and forth along the tracks about five times.
Finally, using a clean q-tip and rubbing alcohol, clean the lens and then dry it off with a dry q-tip.
Reassemble all covers and screws and plug the player in.
Should be good as new! No grantees, but it’s worth a try.
feel free to email me if you still have any issues and I'll try to help.
sewellp@yahoo.com
Patrick Sewell
January 2008