What was found
ON MLG UP SELECTION, RECEIVED A/SKID INOP CAUTION FOLLOWED BY PARK BRAKE SOV CAUTION. NOTED AN AIRFRAME VIBRATION. MLG LEVER SELECTED IAW SOP, UP BUT FOUND MLG INDS TO BE DOWN & 3 GREEN. ON SELECTING MLG DOWN, CAUTION MESSAGES EXTINGUISHED & LANDED UNEVENTFUL (FLIGHT 5737) REF AML 1946617, AML 1946618, & AML 194662. PERFORMED MLG RETRACT TEST, COULD NOT DUPLICATE PROBLEM. SUSPECT PSEU BAD DUE TO NO FAULTS LOGGED IN PSEU CORRELATED TO MLG NOT RETRACTING WHEN SELECTED UP, & NO MLG DISAGREE ON EICAS WITH HANDLE UP, & ALL 3 GEAR INDS SHOW GREEN. INSTALLED A NEW PSEU IAW AMM 32-61-05-04. OPS CHKD GOOD. VIBRATION DUE TO MLG NOT RETRACTING AS INDICATED BY 3 GREEN DOWN & LOCKED INDICATORS.