Do I need a new Course Computer or is there a ghost on the boat?

[tudorsailor]

I have a Raymarine ST6000 autohelm and type 300 course computer both from 2001. For reasons that are not clear the autopilot recently occasionally says no link and this is cured by turning the instruments off and on. Then one day I found that the heading displayed by the head unit bore no relation to the actual heading. This was cured by swinging the compass and doing the three complete 360 deg turns. It stayed correct for the next 10 days.

The most worrying thing was when we were at anchor enjoying an evening drink. All the instruments were on, and the autopilot was sitting at "standby". Suddenly the steering wheel turned itself until it was at full lock to port. At first I thought that something was under the boat turning the rudder which obviously there was not. It seemed the autopilot had engaged and was trying to steer to a waypoint. However the display still said standby and I could could not turn the wheel back to centre. I turned the power off and then I could turn the wheel

Local Raymarine man says that all of this is due to a faulty course computer. He does not have a replacement PCB for such an old computer so it seems that replacing the course computer with a new one is the only expensive answer.

HAs anyone else had their course computer fail in this manner????

TudorSailor

 

[Lon nan Gruagach]

If it were mine, I would first re make all connections and clean all that are ready made plugs.
If it continues then have a look at the PCB a good clean might sort it out.
As a rule electronics dont intermittently fail, its usually a physical component associated with it, so connections and circuit board. One test is to carefully try to flex a PCB if that triggers the fault then there is a loose solder joint.

 

[oldvarnish]

HAs anyone else had their course computer fail in this manner????

TudorSailor

Yes, very similar symptoms except the phantom wheel turning. Your man is probably correct in his diagnosis. Incidentally, mine was of a similar age.
My engineer managed to pick up a computer refurbed by Raymarine (although not a type 300) and that saved a few 100 quids.
But the connections check as advised above is well worth a try first.

 

[ex-Gladys]

No mobile phone in the vicinity by any chance??? Had the same effect (albeit ancient Navico WP) when I just happened to put mobile down adjacent to control head

 

[Yngmar]

If it were mine, I would first re make all connections and clean all that are ready made plugs.
If it continues then have a look at the PCB a good clean might sort it out.
As a rule electronics dont intermittently fail, its usually a physical component associated with it, so connections and circuit board. One test is to carefully try to flex a PCB if that triggers the fault then there is a loose solder joint.

+1 Might just be a wet plug or a strand that came off a wire and is touching something. Check the whole thing end to end and sort anything dubious looking before you splurge on a new piece of kit.