As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY POWER SUPPLY P/N 501-1712-02, S/N 2137 WAS REMOVED FOR SCHEDULED BENCH CHECK ON 3/18/04. ON 3/31/04 UNIT FAILED BATTERY CAPACITY CHECK. BOTH BATTERY PACKS P/N 549-1324-06 WERE REPLACED AND UNIT WAS CHARGED. ALL SUBSEQUENT CHECKS WERE GOOD IAW CMM UNIT WAS RETURNED TO SERVICE 4/2/04.