What was found
"ON DESCENT, GOT " PITCH TRIM" CAUTION. "AUTO TRIM FAIL" ON PFDS TRIM INDICATOR IN FULL NU POSITION. PITCH TRIM DID NOT WORK." REMOVED FROM SERVICE. "DID RETRIEVAL OF DATA FROM CDS. PERFORMED OPERATIONAL CHECK OF ELEVATOR PITCH TRIM. PITCH TRIM CAUTION AND AUTO TRIM FAIL STILL REMAINED. REMOVED FLOOR PANEL 133EZ IN REF WITH Q400 TASK 27-00-01-000-802. R&R FCECU IAW AMM TASK 27-00-01-000/400-002. OPS CHECK GOOD "PITCH TRIM" CAUTION NO LONGER ILLUMINATED AND NO "AUTO TRIM FAIL" ON PFDS. C/W OPC OF ELEVATOR TRIM CONTROL IAW Q400 AMM 27-32-06-710-801. NO DEFECTS NOTED. AIRCRAFT RETURNED TO SERVICE.