Furuno FS-5000 - Confirmation of Jumper Settings; Speaker and Handset Volume

REMOTE
I1-12
3.2 Confirmation of jumper settings
To confirm jumper settings of JP1 and JP6, turn on the power while pressing and holding
down the [ENT] key.
To confirm jumper settings of JP4 and JP5, turn on the power while pressing and holding
down the [HOOK] key.
3.3 Speaker and handset volume
Speaker
Adjust R18 with the VOLUME control on the front panel set at maximum for desired
speaker volume.
Handset
Adjust R9 to select desired handset speaker volume.