My ST60's have not faded, but my ST50 that is many years older (15) did eventually fade away despite my best efforts to keep them covered as much as possible. As to whether fading is related to other
electronics in the autopilot system, I would say probably not, but it likely depends on which CorePak computer unit you are using with it---some of them have pathetic fusing in them, and others have very good fusing. So it would depend.....I have blown the control heads out with some of the old
Core computer units that were inadequately fused---but that was blow out and not simple display fading. I am really helpful, aren't I?
The flipping to standby could be a some reversed wires on your computer. I believe that Raymarine's self help website has a diagnostic for this problem that I used to fix that problem when I had it. Also, depending on how you have wired your ST 60
instruments and linked them to the Autopilot. If you are not careful, you could be supplying the
power for the drive unit through your instrument circuits which will cause your
fuses to blow in the computer and the unit to go to standby spontaneously. Your ST60
instruments (in some versions--I think
RayMarine fixed this in others) should be only powered through the autopilot circuit (so you always turn on the autopilot circuit for all your ST60 instruments--even though you have not engaged the autopilot to control the boat). So the ST60's should not be on a breaker and line of their own because they will connect through the hot wire of
SeaTalk and try to drive the autopilot in those little wires---which will
work until it draws enough
current to blow the fuse or force it to go to Standby.