These are some common tools used to work on this device. You might not need every tool for every procedure.
Figure out what may need to be fixed by checking out Panasonic DVD-RV31 Troubleshooting
This device is easily identifiable by the "DVD-RV31" model number on the front panel, on the left of the CD Drive.
This device was released as an entry level dvd player by the Panasonic Corporation May of 2001 and was sold for under $200. It is a progressive dvd player, as opposed to interlacing, meaning that it scans each line of pixels progressively, rather than by scanning the even then odd lines. It was often noted as having fluid fast forward and rewind capabilities. With a multitude of features and good reliability this device was very popular for many years.
AVS Forum - Information about certain error codes
Owners Manual - Original Operating Instructions
Panasonic DVD-RV31 Player Review/Overview - A review of the dvd player from when it was originally released. Also contains information about performance, features, etc.