[TG] [TG11] Fluxgate compass / course computer troubleshooting

[Tom - Raymarine - Moderator]

Hello Tony,

In what way is the heading wrong? Does it:

1. seem to respond normally as you turn and give heading values that look correct except that the heading appears rotated? This would probably indicate that the course computer's EEPROM non-volatile memory were no longer storing the calibration offset. This can't be repaired but the pragmatic workaround would be to fabricate a bracket to rotate the fluxgate into the correct orientation. Or replace the pilot...
2. lag as you turn the boat, or drift when not turning? If this is not related to specific headings but occurs all the way through 360 degrees then it's likely a failed Rate Gyro. Does the problem go away if you remove the grey plastic cover and unplug the 3-pin white rate-gyro connector half-way up the left-hand edge of the board (do this when powered off)? This would revert it from S2G to standard S2 and would get you going again with reduced steering performance. The replacement gyros were a spare but probably aren't economic to try to source now.
3. appear to indicate correctly through part of the turn or at some times or in some directions and then not in others? This usually indicates a fluxgate problem still. Fluxgate broken windings can be frustratingly intermittent and I always treat 'pass' measurements with suspicion: I sea-trialled a boat in Turkey once, 3 days in a row, and only on the third day did the long-running intermittent problem show up.
   

If you can describe the heading problem more explicitly then I can probably give you a more concrete diagnosis.

Regards,
Tom