Inspect physical condition
Check mounts, cables and connectors for damage, moisture or corrosion, following manufacturer precautions. Electrical work should be performed by competent people.
Check data sources
Power the system and verify position, heading, depth, wind and AIS where installed. Confirm that readings update and screens use the intended sources.
Updates and backups
Review software and charts before the season, keep configuration backups and test startup after changes. Document faults and do not leave the first check until departure.
A maintenance record
List models, versions, last update and configuration backup locations. Inspect mounts, connectors and moisture with power disconnected where appropriate. Document faults before intervening.
Check the complete system
Start from cold, inspect sources and updates on each display and open local charts without internet. After an update, repeat tests and keep a recovery procedure and alternative resources.