I saw someone a while ago on telegram complains about the same thing, I think one of his miners needed a PSU and the host wouldn't do it, they provided to ship it to him and then he had to change the PSU and send it back, the cost of shipping + the downtime cost a lot more than paying someone to do the job, this is why I don't like my miners to be hosted by some random person that is a few thousand miles away, and should that be your only option, you should at least check their terms and sign a contract that "forces" them to do the basic maintenance such as disconnecting hashboards, swapping PSUs and all that.