As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY CHECK FOUND MULTIPLE CEILING EMERGENCY LIGHTS INOP (AIRCRAFT IN HEAVY CHECK FROM 1/11/2013 UNTIL 1/30/2013). REMOVED AND INSTALLED EPSU BATTERY PACK 2 IAW CRJ 900 AMM 33-51-17, OPERATIONAL TEST OF EMERGENCY POWER SUPPLY UNIT GOOD IAW CRJ 900 AMM 33-51-17-710-801.