Furuno FELCOM 12, Service Manual

Page: 68 / 118

5-11
5.7 Replacement of Backup Battery
The life of the lithium battery on the CPU board is about five years. The longer the time
when the unit is off, the shorter the life of the battery.
CR 7
CR 8
CR 9
CR 2
CR 3
CR 4 CR 5
CR 6
TP4 TP5
S1
U39: ROM
U44: DEMOD
ROM
BATT
BUZZER
U11: EE-PROM
TP1
TP3 TP2
U11 (M6M80041P): EE-PROM
Forward/Return ID programmed
BACK UP
•
U40 (SRM20100LLM70): SRAM
•
U36 (RTC62423): TIMER
JP1
BACK UP ON/OFF
U40
U36
Figure 5-5 CPU Board
•
Battery Type: CR 1/2 8L-F
•
Code Number: 000-103-769
Note)
Remove JP1 when replacing the battery soldered. The settings backed-up by the
battery is listed on page 5-7. The figure below shows the outline of memory back-up
circuit.
BT1
JP1
U17
VBAT
VOUT
(CPU
monitor)
U40
U36
(SRAM)
(RTC)
VBAT
(GPS)
GN-74
J8-5
CPU (16P0148)
Figure 5-6