As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER LANDING OVERHEAD MAINT AMBER LIGHT ILLUMINATED. GROUNDED - YES. FOUND FAULT CODE 21-55010 VERIFIED LEFT PACK EXHAUST ACTUATOR HAS FAULT AND IS NOT WORKING REPLACED LEFT PACK EXHAUST ACTUATOR REF B737-9 AMM 21-51-27 OPS GOOD MX LIGHT REMAINS EXTINGUISHED.