Furuno NavPilot 511 (Processor 5002) keeps shutting off

[dominic93]

Hi everyone,

I’m having an issue with my Furuno NavPilot 511 connected to a 5002 processor unit. I just sailed about 500 nm without a single problem, but this morning the pilot started acting up.

After powering it on, it runs normally for a few minutes in Auto mode and then suddenly shuts itself off. No alarms, no obvious warnings — it just drops out. Sometimes, after it shuts down, I can’t turn it back on immediately. It will only power up again after a few minutes.

Battery voltage is steady at 13.2 V at rest and around 12.9 V with the auto pilot motor running, so the supply appears stable. The 13.2 V is present even when the pilot refuses to power back on.

Has anyone experienced similar behavior? What could cause the NavPilot to repeatedly power off and sometimes not turn back on right away? Any ideas on where to start troubleshooting would be greatly appreciated.

Thanks!

 

[Titanic II]

See how much current the motor is pulling while dodging it back and forth. If it is pulling too much the processor will shut down.
If it isn't that it is most likely the power board in the processor unit (FAP5002) has a power current transistor (FET) bad or going bad.

 

[dominic93]

Thank you for the fast reply,
I checked it and my multimeter shows up to 7A while dodging back and forth.
Mh, the last 500nm the autopilot was also steering a lot with the maximum steering speed.

Right now it shut off without any steering movement.

How can I check the transistors? Can I just replace them?
So when the Autopilot fails, I can hear the standard relais click. Same sound when I switch it off normally.

What about the DCDC converter? Can they fail and just release the 12V relais?

I'm planning an ocean crossing soon and would like to have a working autopilot

 

[dominic93]

Okay, now after 20 restarts, the pilot is not switching on anymore. The last few times it switched on and after a few seconds, even before the self check, it switched off immediately.

 

[Titanic II]

If it is not powering up at all, it is not the FETs or another part of the board has gone bad also. 7A current draw by the motor is fine. If you get the silk-screened number off the power board (the one the ship's mains and motor connect to) I can check if we can still get it. The number will be one of these: 64P1141-66; 64P1141-77; or 64P1141-88.

**CAUTION** This is an assumption on my part that it is the power board. To know for sure, you would have to send us the processor unit for proper troubleshooting to be done. But first, let's see which power board you have in there because if we cannot get the board anymore replacing the Navpilot would be the only option.