As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BURN SMELL INFLIGHT. INSPECTED AND OPERATED BOTH PACKS USING APU AND ENGINE BLEED FOR SEVERAL MINUTES. DID NOT NOTICE A BURN SMELL. ALSO INSPECTED ALL CABIN LIGHTS FOR ANY SIGNS OF BURN MARKS OR FALSE CONTACT. COULD NOT FIND ANY DISCREPANCY. R & R UNITS AT 10 A/B & 11 C/D FOR TEST. OPS CHECK GOOD AT THIS TIME, PN: BR9500-5.