What was found
BURNING SMELL AFTER APU BLEED USED IN FLIGHT DECK RT PACK LIGHT ON APPLY MEL 2151, RT PACK LIGHT ON MEL 2151T ONE PACK INOPERATIVE - APU OPERATES NORMALLY. BITE TESTS PASSED NO FAULTS BUT LIGHTS ILLUMINATES AFTER 1 MIN OF RUNNING THE RT PACK. ESC PACK OFF WITH AFFECTED SWITCH OFF. COMPLIED WITH MAINT ACTION. STICKER APPLIED *DM* SEE M/L FOR ACM, PACKINGS, GASKET & FLEX DUCT, IF NEEDED. FOUND RT PACK ACM SEIZED. R & R RT PACK ACM. PERFORMED RT PACK AIR CONDITIONING, SYSTEM TEST, AIR CONDITIONING IBIT - PASS. SUPPLIED CONDITIONED AIR WITH THE RIGHT COOLING PACK - NO SMOKE NOR FUMES NOTED. REF AMM 21-51-04.