Autopilot abrupt U-turns

[SheltieJim]

I have a fairly extensive Raymarine system on my 40' sailboat, including an X-30 autopilot, an ST70p controller, and a Type 2 Short electrical actuator, as well as a rudder position sensor and a fluxgate compass. I also have an e95 MFD at the wheel and an e127 (which just replaced an e125 that abruptly failed a few days ago) at the nav desk.

Twice yesterday, the autopilot suddenly made a hard left turn. In one case, the boat had turned 180° before I could get the ST70p to turn the autopilot to Standby; I suspect, but do not know, that the hard left would have continued longer. The second time, I managed to gain manual control (Standby) before the boat had turned 90°.

In both cases, when I looked at the ST70p display, it appeared to be re-booting. After it completed whatever it was doing, the autopilot resumed normal function (until the next time, of course).

What could possibly be happening to cause this? It could be fatal under certain circumstances (e.g., if it suddenly turned me in front of a high-speed power boat or ran me up onto rocks).

I am especially disturbed by the behavior when the ST70p appears to reboot. I would think that the safest behavior for an autopilot that suddenly loses its controller would be to continue in precise the direction it was already headed, not make an abrupt turn to port.

In the interests of full disclosure, I should mention that it's possible that I may be having an electrical power problem. I recently installed a Ray70 VHF with a Remote Mic and I sometimes get the message "Inadequate voltage" or something similar when powering the remote mic on. In addition, a few days ago, my e95 abruptly decided to reboot in a very dicey situation.

HELP!
Jim