As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB WHILE PERFORMING A/I TEST CABIN PRESS RATE JUMPED TO 3200FT/MIN. THEN DURING DESCENT CABIN PRESS RATE SPIKED TO 2000FT/MIN. AT LEVEL FLT CABIN PRESS RATE SPIKED TO -400FT/MIN. DURING ANOTHER DESCENT CABIN PRESS RATE SHOWED CLIMB TO 1000FT/MIN. R/R'D DIGITAL CONTROLLER PER MM 21-31-01. PERFORMED AUTO PRESSURE OPS CHECK PER MM 21-31-00-700-802-A.