What was found
DURING A HEAVY CHECK, EMERGENCY LIGHT BATTERY 11WL FAILED TO TEST THRU MCDU. REMOVED AND REPLACED EPSU ASSY IAW AMM 33-51-38-PB 401, CONF 00. OPS CHECKED GOOD. AIRCRAFT RETURNED TO SERVICE.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
DURING A HEAVY CHECK, EMERGENCY LIGHT BATTERY 11WL FAILED TO TEST THRU MCDU. REMOVED AND REPLACED EPSU ASSY IAW AMM 33-51-38-PB 401, CONF 00. OPS CHECKED GOOD. AIRCRAFT RETURNED TO SERVICE.