During our 20 day Atlantic crossing earlier this year we noted that our Simrad AC42/AP28/NSS7 stopped working on a regular basis with an error message on the displays (AP28 and NSS7) saying: No Autopilot Computer. Pressing STANDBY and then AUTO again solved the problem and the autopilot did its work wonderfully for another 24 hours. During many days the error was so regular that we sat in front of the AP28 waiting for it to occur and sometimes it did, even on the minute exactly 24 hours after the previous error. Sometimes it differed five or ten minutes but still very close to 24 hours between errors. Pressing STANDBY+AUTO always fixed the problem and gave us another 24 hours of good work.
I downloaded the erorlog from the NSS7 and we could see on the timestamps that it was often exactly 24 hours between alerts.
Does anybody here recognize this annoying behaviour ?