As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOTH PACK CONTROLLERS ARE FAULTING THE ALTITUDE SW(<P>REMOVED AND REPLACED PACK CONTROL ALTITUDE SWITCH IAW AMM 21-51-17, PERFORMED BITE TEST ON PACK TEMP CONTROLLER PER TASK 21-51-14-705-035, OPS TEST GGOD. NO OTHER DEFECTS NOTED AT THIS TIME<BR /></P>)