Lulzbot mini homing issues

So I have had this printer for about 3 yrs. Upgraded board installed lcd screen and even replaced toolhead. Prints were coming out perfect and then all of a sudden a print failed. Tried to reprint and when printer started homing cycle toolhead rose up to the top and end stop never stopped it kept running until it errored out and homing failed please reset appeared on lcd screen. I replaced endstop with new one, but problem still exists. Please help