What was found
WHEN AT IDLE OR CLOSE TO IDLE THRUST DURING DESCENT, CABIN PRESS RATE CLIMBED AT 1000 FPM FOR APPROXIMATELY 5 TO 10 SECONDS BEFORE STABILIZING. THIS HAPPENED EVERY TIME THRUST WAS AT OR NEAR IDLE. PERFORMED OPERATIONS CHECK OF THE PRESSURIZATION CONTROLS IAW AMM 21-31-00, OPERATIONS CHECKED GOOD. PERFORMED FUNCTIONAL TEST OF CABIN PRESS CONTROLLER IAW AMM 21-31-16, FUNCTIONAL CHECK GOOD. OK FOR SERVICE NO DEFECTS NOTED.