when your hash board temp rises your control board kill hash board and stop mining or restart s17+ because bad core or high temp.
your hash board have 4 temp sensor and read your temp from every chip and send average temp to control board.
when your hit sink on chip lost, your chip warming deadly and your fans can't get cool your chip, cause your hash board didn't damaged control board power off hash board or restart to hash boards get cooler.
that work only 5-10 min.
better way replace your asics and put your hit sink on chip with solder in s17+.