Lite On 5007 Invalid disc

My 5007 was working fine, then all of the sudden, every blank media disc and store bought DVD movies have an "invalid Disc" error? Anyone know what to do? I restored it, unplugged it....help?

I have had / got the same problem with my 5045 (?UK model of 5007). I haven't received any answers on this forum as yet.
It gives the "Invalid Disc" message for blank media, previously burned discs and precorded discs as well. It does recognize +RW discs and audio CDs though!
I hope you are successful in sorting out your problem, 'cos if you get sorted the "fix" might help me as well.

My 5005 has started to do this with about 5 different MIC DVD's after they were recorded to and I watched what was on the DVD but did not finalize it.. I called LiteOn and they said to RMA it.

Have you tried a DVD lens cleaner (not the wet type)?

Debris will collect on it causing problems in reading as it cannot see through the "muck", every home has masses of the stuff and even laying a disc on the sofa before putting it in the machine will cause a fair bit of dust transfer.

Mine did the same thing, I had to send it back (RMA) to Lite-on after they tried to come up with every reason why it was my fault or my media's fault. Nothing would burn in it at all and I was getting the read errors yet somehow it was the media's fault. It was like I had to twist their arm off to admit the thing was junk. It's supposed to come back to me Friday. A replacement. Guess it was broke, jerks.