The CD isn't reading the disk, so it reports "blank disk". It could be as simple as the CD laser lens having dust or lint on it, in which case you can use a CD cleaner disk (available at Walmart or Radio Shack, Best Buy, etc.). If that doesn't help, the second most common problem is that the laser lens is out of adjustment, and not focusing properly, thus not reading the CD. This can happen with slight wearing of mechanical parts, or any change in the detection circuity (aging of capacitors, etc.) This can be corrected, but it entails taking the unit apart and adjusting the CD lens on a trial and error basis (adjusting, then trying, until you get it right). Here's a web blog on the procedure, and it will clue you in on what you can try. If you don't feel like tackling it yourself, of course, you will have to have the unit serviced. Get an estimate first, since it's also possible that they will just replace parts, or possibly a circuit board, in the event that adjustment of the lens doesn't solve the problem. Here's the blog:
Good luck, and hope this helps!