Troubleshooting; Error Messages; Led Status; Selftest - Furuno GP-90 Service Manual

4.1 Error Messages

Table 4.1 lists error codes .
Error message
GPS No fix
DGPS error
GPS SELFTEST
error

4.2 LED Status

CR7 on NP board indicates the status of MPU (U16).
Board
20P8188

4.3 Selftest

Selftest is performed through SELFTESTS menu.
1) Memory and I/O circuits test
1.Press [MENU] and then [8] to display the SELFTEST menu.
Table 4.1 Error messages
Possible cause
When GPS signal is suddenly
lost.
DGPS beacon station is
experiencing transmitting
problems.
If the selftest (conducted when
turning on the power) finds any
error.
Table 4.2 LED
Parts No.
CR7
SELF TESTS
1.Memory, I/O Port Test
2.Keyboard Test
3.Test Pattern
4.Automatic Testing
GPS PROGRAM No.4850237003
NAV PROGRAM No.2051512-02.xx
BOOT PROGRAM Code B
!" : Cursor
ENT: Enter MENU: Escape

4. Troubleshooting

1) Check antenna connections.
2) Replace GN-8091 board.
1) Check DGPS coverage.
2) Replace beacon receiver.
1) Replace GN-8091 board.
(Disconnection between GN-8091
and NP board does not generate
this message.)
Remarks
Blinks every second to indicate
normal MPU operation.
xx: Version number
10
Action