Sony MAV-555 Maintenance Manual page 22

1-5. Upgrading the Software (PU-109 board)
Audio
Preparation
1. Connect CN801 of the PU-109 board and a personal computer using the RS-232C tool cable.
2. Set the Audio-Video switch of the system set-up panel to Audio.
3. Set S1101-7 of the PU-109 board to ON (lower side).
4. Set the S400-7 of the PU-109 board to OFF (upper side).
Download procedure
Perform the download procedure of Video from steps 1 to 7.
Setting after download is completed
Set S1101-7 of the PU-109 board to OFF (upper side).
1-12 (E)
MAV-555