JRC JMR-92 Series Field Service Manual page 858

Note
It is recommended that the DVD drive is cleaned at least once a month. If the lens becomes
dirty, it may not be possible to read data from a CD/DVD, or else it may not be possible to
install a chart or an update.
When reading the lens cleaner CD fails, an error dialog box appears.
7.2.12 Cleaning the Trackball
Refer to "4.3.4.2 Cleaning the trackball" of Chapter 4.
7-35 Chapter 7 Troubleshooting