As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
P6-4 BLEED AIR VALVES LEFT CIRCUIT BREAKER FOUND OPEN DURING PRE-FLIGHT. GROUNDED - YES. P6-4,A7 C796 C/B POPPED OPEN AFTER RESET REF SSM 36-11-11-102 REMOVED CONNECTOR DP1102 FOR #1 ENG BLEED AIR REGULATOR M1180,CB STAYS IN WITH #1 ENG BLEED SWITCH ON. REMOVED AND REPLACED THE #1 ENG BLEED AIR REGULATOR PER B737-800 AMM 36-11-03-000/400-801. OPS AND LEAK CHECK GOOD. RAN #1 ENG FOR 3 MIN WHILE CYCLING #1 BLEED AIR WITH NO DEFECTS. CB DID NOT POP.