Mine had the problem for a while, (before it RROD'd) and I know this is sort of a homage to the NES days, but while the disc tray is open... spray some compressed air into the system.
It might be that a spec of dust has settled onto the lens. If you don't have a can of compressed air, just blow into the system.
try different dvd's.
turn the system upright, maybe that will work.
these are all forms of troubleshooting that should be done before you take it back.








