In article ,
Dan Best wrote:

Molesworth wrote:
I have an ST4000 autohelm.
When Control Head is switched on the display reads 331deg, regardless of
which way I am heading.

I had a similar problem develop with an ST-3000. Fortunately, it was
still under warranty, so I sent it back and they replaced the compass unit.

And there is no way to service it yrself? I have been told that it may
well be this item thats at fault.

Molesworth