Since the original power supply is dead, and the new one triggers an overcurrent protection, it’s clear that issue lies with an MOV, which is a surge protector within Rachio controller.
Seems it has done it’s job and protected the controller, unfortunately it seems to be now shorting.
Repair is pretty cheap and easy, in case you (or your friend) are comfortable with a soldering iron.
There were several discussions (link) on the movs, usually this issue occurs when new users try to use original supply overseas.
