NAV won't read DVD map CD.
 

I was driving my 2006 GS300 and my navigation says I need to insert the DVD map CD. The CD is in there. I ejected the DVD map CD and reinserted and it still won't read the CD. I already make an appointment with the dealership so they can take a look at it. But, I just want to know if anybody else have this problem before. If you have. Did you fix it yourself or did the dealership do it? If you did it yourself. How did you fix it? I want to avoid the dealership if I can. If they have to take out the DVD player and replace it. It won't go in the same way. Meaning, something problem start to rattle. The dealership replace a bad speaker in my 2002 GS300 before and my door panel started to rattle. That's why I try to avoid the dealership if I can.

Thanks in advance.