Six network faults on a yacht stabilizer
The job you are buying is named on the rule. These six are the reasons a helm page goes blank while the machine is still a machine. None of them is a reason to split an actuator.
The short version
Compare the local display to the helm. If only the helm is dead, stay on this list. If both are dead and the history says vacuum, leave for the vacuum checks. If oil is on the deck, leave for the seal list.
| Fault | What you see | What you do not order |
|---|---|---|
| Presence light only | Helm box pulses, no text | A sphere |
| Gateway asleep | Local display alive, MFD page empty | A fin seal |
| Power dip on spin-up | Page drops as RPM climbs, returns later | A new controller on the first dip |
| Duplicate address | Two devices, one page, intermittent ID | A haul |
| Bad termination | Works at the dock, fails when a cable is moved | A rebuild |
| Local run, helm dead | Fins or gyro answer at the unit | A steering write-up, unless the changeover test actually fails |
How the six were ranked
First place is the mistake the Seakeeper 1 operation manual already warns about: the ConnectBox is not the alarm identifier. Second is the split between a live local screen and a dead helm, because that split ends the vacuum theory. Third is the power dip, because spin-up current is when gateways reset and because the same manual discusses repeated AC interruptions as their own warning. Fourth and fifth are address and termination, the two physical-layer faults that survive a software reset. Sixth is the inspection trap: on a certificated boat, 46 CFR 61.20-1 still wants the steering changeover demonstrated. A dark page does not fail that test. A locked hydraulic plant that prevents the test does.
- Presence light only. Read the display application. The box at the door is not the diagnosis.
- Gateway asleep. Wake or reseat the gateway before you condemn either housing.
- Power dip on spin-up. Watch supply voltage as the flywheel comes up. Log repeats. Do not replace hardware for a single transfer.
- Duplicate source address. Two devices claiming one identity will look like a random dropout. Find the second device.
- Termination and a cable that moves. A network that works until someone shuts a locker is a connector, not a bearing.
- Local control still runs. Use it. Then, if the boat is certificated, show manual steering anyway. See the Duval inspection note when the zone is Sector Jacksonville.
Questions from the wheelhouse
If the local display works and the helm does not, is the gyro failed?
No. The Seakeeper 1 manual separates the ConnectBox, which only shows that an alarm exists, from the application that identifies the alarm on the display or the multifunction display. A live local screen and a dead helm page is a path between them, not an enclosure that lost vacuum.
Why does the page die when the flywheel spins up?
A voltage dip when a large motor starts will reset a gateway that was barely supplied. The Seakeeper 1 sheet notes that the machine rides through short AC interruptions and warns when those interruptions repeat. Count the dips before you replace a display.
Does a network fault fail a Coast Guard steering inspection?
Only on a certificated boat, and only if you cannot show the automatic-to-manual changeover the inspector has to see. That clock is the Duval note for Sector Jacksonville, and the same steering section applies in other sectors. A private yacht is not on that clock.
Should every ranked item get a different technician?
No. One callback covers the fault once you know it is the network and the boat is in Florida and in spec. This list is how you avoid sending a seal kit or a sphere for a cable.
When the fault is named, go back to the rule and use the callback if the boat is in spec.