Over time dust and stuff can accumulate on the lasers that read the discs. You should try a dvd laser cleaner (its different then the disc cleaner you might purchase for a cd player). Its a disc that has a little brush on it. You insert it into the DVD player, you may need to run it 2 or 3 times, but when you use it, the little brush will clean the laser off. Another problem could be that sometimes the laser becomes mis-aligned, inhibiting the DVD players ability to read the discs. I would try the laser cleaner first as the only way to get the laser re-aligned is to take it to a service center and get it repaired. Our old PS2 stopped reading discs and my husband actually took the lid off of it and used a q-tip with some of the laser cleaner that comes with the dvd laser cleaner kit to clean the laser off - we're smokers and pet owners and it was just plain disgusting how dirty that little laser got! After that it ran fine and read all the discs that we thought had some how gone bad.
There are other possiblities too such as a bad laser motor, bad spindle motor (although I think this one is unlikely since you can hear it spinning) and other circuit related issues that can be causing your bad disc error. However these things would need to be diagnosed by an authorized service center.
I would say that as a general rule of thumb, if the cost of repairing exceeds 2/3 of the cost of a new unit, I would just buy a new one.
If you have any additional questions, please ask before accepting this answer.
This is all I know about the error you are receiving on your DVD player. I will opt out so that another expert can step in and assist you with your question. Others that have had different experiences then mine may have other ideas.
If you put an audio CD in the machine will it play a commercially recorded music disc?
The reason I am asking is your machne may have dual read lasers and I want to see if anything is working.
However before you put the disk in can you unplug the unit for about 30-60 seconds and plug it back in.
Then let me know about the music.