What was found
AFTER UNLATCHING THE MAIN CABIN DOOR HANDLE, THE DOOR DID NOT OPEN AND NEEDED TO BE FORCED TO START DOWN. AFTER ENGINE SHUTDOWN AND WITH APU RUNNING. TECH CONFIRMED SQUAWK; WHILE OPENING THE MAIN DOOR, IT REQUIRES LITTLE HELP WITH HAND TO OPEN AND NOTED NOISE COMING FROM AFT RUB BLOCK. COMPLETED GVI ON BOTH RUB BLOCKS, NO DEFECTS NOTED. CONTACTED MCC AND CHECKED HISTORY. NO RECENT HISTORY ON RUB BLOCKS. CLEAN RUB BLOCKS WITH ALCOHOL, MAIN DOOR OPS CHECKED GOOD. OPENED AND CLOSED MAIN DOOR FROM INSIDE AND OUTSIDE 5 TIMES EACH. IT OPENS WITH NO HELP AND NO NOISE NOTED. REF: CE-680A AMM 52-10-00.