[TG] Smartpilot X30 only operating to Starboard

[Java]

Hi there,

My autopilot stopped working a while back so I performed some simple tests and found that the auto-helm would move to Starboard but not Port. Everything else looked ok, rudder reference unit (validated by position showing on ST70) and compass (validated by heading showing correctly on ST70). So I assumed it was the linear motor.

But on doing one final electrical test I've discovered an anomaly. I tested the "Drive Motor Outputs" on both a Starboard and Port tack and I'm not getting any voltage output when I perform a Port tack/adjustment. I expected to see -12v, opposite to the +12v from the Starboard tack, but I'm not getting anything, zero volts.

So then I temporarily reversed the Drive Motor Output cables and validated that the linear motor works correctly (it pulled the rudder to Port and wouldn't push to Starboard with the cables reversed) so that means the fault is with the X30 course computer. It's like there's a relay/Mosfet that hasn't reversed the polarity/provided 12v to the Drive Motor Output cables on the X30.

Any idea where to go next? Test the relays/Mosfet's, or have I missed something bigger?

Thanks for any help or direction.

[Tom - Raymarine - Moderator]

Hello Java,

You're quite right, that sounds like a FET, I'm sorry to say.

Regards,
Tom