What was found
COCKPIT HALON FIRE EXTINGUSHER HAD SLOW LEAK WHILE AIRBORNE. SWAPPED THE AFT CABIN OVER SEAT 37 HALON FIRE EXTINGUISHER WITH THE DEPLETED ON IN THE FLIGHT DECK PLACING THE FWD GALLEY HALON FIRE EXTINGUISHER ON MEL 2603A. RETURNED PREVIOUSLY SWAPPED FIRE EXT FROM FLT DECK BACK TO CABIN. INSTALLED NEW NEW HALONE FIRE EXT IN FLT DECK PER AMM 26-26-01-430-801. RETURNED PREVIOUSLY SWAPPED FIRE EXT FROM FLT DECK BACK TO CABIN. INSTALLED NEW NEW HALONE FIRE EXT IN FLT DECK PER AMM 26-26-01-430-801.ROTABLE PARTS CHG:TT # 1309203 SN OFF 0226 PN OFF 99-2626-9-0002 IPC REFERENCE # DP STATUS UNREADABLE MISSING/UNREADABLE PLATE OPTION WAS SELECTED