Hello.
I got mikrotik (CCR1009-8G-1S-1S+) which does not start at all. There is no enable 3.3V, but 12V is ok. As far as I was able to understand, it should begin from Q1403 (AO4484) managed by U1401. But in none of the troubleshooting documents I did not find the definition of U1401. The worst part is that there is no richtek label on it which can be found by google.
I understand that this is particular question, but I hope, and will be very glad to any help.
Guesswork in progress. According to the circuit design of 1100r3, U1101 should do the same. It is RT8209B. It seems like.
If anyone is interested. Yes it was RT8209B, but the problem was not in itself.
if you had troubles obtaining parts in you region(currently - most resellers - ship Anywhere, including Oceania and Greenland. one - even accept orders from Antarctica 
, most of which had worldwide delivery from both voice/phone and internet, fax(with callbacks) orders.
in case if they lack such parts - simply use similar DC-DC converter on similar specs (from same or different brand)using “reference” shematics/usage/soldering.