RG Fail w/occasional compass spin 360

[paulpoz]

I bought a used a S1G course computer to replace my ST 5000. It worked fine for about 6 months. Now I get intermittent "RG FAIL" at times whether I'm going to slow or fast. I will also get a hard to port "Crazy Ivan" with no warning, quite often. Other times the compass reading on my 8002 control head seems to continuously hunt going clockwise around the whole compass jumping 20 degrees or so, all the way around, 360 degrees and keeps going and never finds the correct direction. However, all of these are corrected by turning the unit off and then back on, but never holds true for my than about 15 to 25 minutes. I've done all the calibration settings in the manual. The fluxgate compass passed all the tests, so did the rudder sensor. I notice there are many different versions of software out there. Can I upgrade my software myself? Is it still available? Would interfacing the S1G with GPS help? I do nothing fancy with my autopilot. All I want to do is troll or cruise in a straight line. I would assume that Raymarine no longer services these units? Any help that anyone could give me would be wonderful. Thank you in advance! Paul.