4. Troubleshooting
10
4.1 Error Messages
Table 4.1 lists error codes
.
Table 4.1 Error messages
Error message
Possible cause
Action
GPS No fix
When GPS signal is suddenly
lost.
1) Check antenna connections.
2) Replace GN-8091 board.
DGPS error
DGPS beacon station is
experiencing transmitting
problems.
1) Check DGPS coverage.
2) Replace beacon receiver.
GPS SELFTEST
error
If the selftest (conducted when
turning on the power) finds any
error.
1) Replace GN-8091 board.
(Disconnection between GN-8091
and NP board does not generate
this message.)
4.2 LED Status
CR7 on NP board indicates the status of MPU (U16).
Table 4.2 LED
Board Parts
No.
Remarks
20P8188 CR7
Blinks every second to indicate
normal MPU operation.
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.
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
SELF TESTS
xx: Version number