I've had a Gen 1 hanging in my garage for awhile.
It's been acting strange for the past couple months and I finally got to looking at it.
Strange = logs that show power cycles during the times that my watering schedules run.
Strange = Wifi dropouts (that is the problem that prompted me to fix this problem) - reset ALL my equipment and changed wireless settings to no avail even though controller was connected fine for months.
Strange = Unexplained behavior and unexpected results when using the remote console on phone or web
Strange = would not complete blink up process
Strange = removed unit from wall mount (molex connector,sprinkler wire) left wall mount on wall and just had front panel connected to AC adapter and would join wireless network IMMEDIATELY. Put the faceplate back on the base and wireless would drop after a few minutes.
Check your power adapters boys and girls.
Mine was HOT to the touch and the housing was actually cracked due to the heat generated by the defective AC Adapter.
Replaced with another 24VAC 1000ma ac adapter and the Rachio booted right up and joined my wifi network and completed a watering cycle with no power cycles or anomalies.