What was found
L1 DOOR ESCAPE SLIDE WILL NOT ARM. FOUND GIRT BAR OUT OF PLACE. SLIDE AND GIRT BAR ARE STOWED BEHIND RCB. THE SLIDE WOULD NOT ARM. AFTER OPENING DOOR THE AFT GIRT BAR END WAS OUT OF PLACE. AFTER ASSEMBLING THE GIRT BAR, THE ARM/DISARM WORKED UNTIL THE DOOR WAS OPENED AND CLOSED AGAIN. SAME PROBLEM REPEATED. THIS ITEM HAS HISTORY. REMOVED SLIDE AND PLACED AIRCRAFT BACK TO MEL CONIFIGURATION. REINSTALLED L1 PASSENGER DOOR ESCAPE SLIDE AND INSTALLED NEW GIRT BAR. REF B757 AMM 25-66-01-4. OPS CHECK GOOD. MEL CLEARED. A/C OK FOR SERVICE.