This is a good idea.
I am located in NJ , USA
I have sent in 3 boards and 1 controller to The Colorado , USA location of bitmainwarranty
https://bitmainwarranty.com/My 3 boards were sent back fixed
My controller was fixed.
I also purchased 2 spare fans from them.
and 2 spare controllers.
https://bitmainwarranty.com/shop/products/us/fan_s7/ >>>> 25 usd
https://bitmainwarranty.com/shop/products/us/s9-control-pcb-c5/ >>>>> 98 usd
https://bitmainwarranty.com/shop/products/us/s9-io-pcb-no-network-port/ >>>>> 20 usd
Note you need both parts for a complete controller so 118.
Service was good. I screwed up on one repair as I filled out forms wrong and I did not find return emails as they went to a spam filter.
If you are USA this is a good place to get bitmaintech gear fixed. Rather then shipping it to China.
I did a long thread on my warranty adventures. It is in hardware.