I have a JVC DR-MH50 DVD/HD recorder and it will only record on DVD-R or DVD-RW not DVD+R or +RW. so check your format of disk you are trying to record on it may be as simple as that.
Try recording on a re-writeable dvd i had exactly the same problem on a dr-m100 (the more primitive version of the dr-m100s) as follows: -- heard a distinct pop while recording -- after that, an error message indicating that i am trying to record on a write protected disk, even though i am not. recording on standard blank dvd now impossible. -- unit still plays dvd normally, except it takes twice as long to find beginning of program -- wierdly, it still records on re-writeable dvd's. the re-writeable dvd must be formatted correctly. the unit still formats re-writeable dvds normally
Usually answered in minutes!