Replacement Of Battery - Furuno NX-700B Service Manual

7.6 Replacement of Battery

Replace the battery of the CPU board when
When the battery is replaced, all the backed-up received messages are cleared. But the
user-programmed menu settings are not cleared.
Reference:
1. Execute "[MENU] -> Service -> Test".
In the Memory Test, battery voltage can be checked.
Interval for battery replacement
Minimum voltage for backup
Time for voltage drop from +2.5 VDC to
+1.8 VDC
2. Received messages and each setting are stored in the SRAM of the CPU board and
backed up by the battery. The EEPROM compares settings of the SRAM every hour and
update changes, if any, to back up data of the SRAM.
For instance, if the battery is replaced immediately after a setting is changed, the changed
setting has not been stored in the EEPROM yet and previous setting data is sent to the
SRAM. As a result, it follows that "setting has not been changed".
Battery: CR2450 F2ST2L
(Code No.000144941)
Item
When newly installed
display voltage
J7
Fig. 7.5.1 Replacement of Battery on CPU board
is displayed in the Status display field.
Value for reference
5 to 10 years
+3.3 VDC
2.5 VDC or less
1.8 VDC or more
1,000 hours at the shortest
1. Disconnect the plug J7 and replace
the battery. The battery is secured
with silicone rubber. Remove the
battery exercising caution so as not to
damage other parts.
2. When a new battery is installed,
secure the battery with silicone rubber
as the old battery was.
3. Connect the plug J7.
7-20
7.6 Replacement of Battery