As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE CLEANING HEAT EXCHANGER, FOUND RIGHT PRIMARY PLENUM BROKEN. GROUNDED - YES. REMOVED RIGHT HAND HEAT EXCHANGER AND PLENUM DIFFUSER IAW AMM 21-51-03. INSTALLED NEW PRIMARY HEAT EXCHANGER & NEW PRIMARY PLENUM RT SIDE REF AMM 21-51-03-400-804-002. ALSO INSTALLED SECONDARY HEAT EXCHANGER AND PLENUM REF AMM 21-51-03-0-804-002.