Hi,
I Was Buy A Microtik Rb1100 ahx4 Last Month.
But Unfortunately This Microtik Is Autometic Shutdown (1hour, 20 minitues letter, 6 hours letter) Without any permission But Do not Start. But Start when, We Unplug and again Plunging Electrics.
Please Help Me
I also have an UPS
I was updated Os Arm 6.47.4.
and Scheduler Is empty.
Please Help Me.
Why I facing This Problem 
As a woman, I am excluded.
Generate a Supout.rif file immediately after the crash and email Mikrotik or generate a support incident.
https://wiki.mikrotik.com/wiki/Manual:Support_Output_File
https://mikrotik.com/support
RMA. I have installed on a school this RouterBOARD and for months with the device up, not problems and it is without UPS.
Actually it is working for more that one year.
Regards.
Shot in the dark…Bad Power Supply. Plug in POE into the ethernet port POE in to rule the internal power supply good or bad