As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHX-DFW - FLT 544 - DURING CRUISE, THE NR 2 BLEED VALVE CIRCUIT BREAKERS POPPED AND WOULD NOT RESET. PILOT ELECTED TO RETURN TO PHX DUE TO KNOWN ICING CONDITIONS. AC LANDED WITHOUT FURTHER PROBLEMS. MX REMOVED AND REPLACED NR 2 ENGINE BLEED AIR SHUTOFF VALVE PER MM 36 11 11 PG 401. OPS CHECK GOOD, AC RETURNED TO SERVICE. (Z)