NORTHROP GRUMMAN Sperry Marine NAVIGAT X MK 2, Assembly Instructions Manual

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NAVIGAT X Mk 2 056341 Rev. AA
7: Troubleshooting / Corrective Maintenance Page 7-1
7 Troubleshooting / Corrective Maintenance
7.1 Troubleshooting Instructions
The NAVIGAT X Mk 2 is a complex electronic system. In case of malfunction, it
would neither be practical nor economical to carry out troubleshooting and
servicing in the field down to the level of individual components.
Unless otherwise instructed by Sperry Marine engineering, field service per-
sonnel should limit troubleshooting to:
– Visual inspection of mechanical components, the main PCB and wiring.
– Continuity checks of wiring connections.
– Checks for overload conditions or reversed polarities. These conditions are
indicated by red LEDs on the main PCB.
– Checking for on-board voltages and I/O signals. The presence of voltages
and signals is indicated by green LEDs on the main PCB.
Exact voltage levels must be checked with a voltmeter. The data content on
serial I/O lines must be checked with the aid of suitable analyzing tools.
When components on the main PCB, other than socketed ICs, are assumed to
be the cause for malfunction, the complete PCB assembly, stock no. 20130, is to
be exchanged.
When components on the baseplate assembly are assumed to be the cause for
malfunction, the complete baseplate assembly, stock no. 22407, is to be ex-
changed.
7.2 Parts Location on Main PCB
7.2.1 Diagnostic LED indicators
Fig. 7–1:
location of diagnostic
LED indicators