What was found
BLEED 2, LEAK AFTER E1 START. BLEED CONFIG WAS: APU BLEED OPEN, X BLEED OPEN, BLEED 1 & 2 CLOSED AND PACKS 1 & 2 ON PASSENGER ALSO REPORTED ELECTRICAL BURNING SMELL APPROX MID CABIN. PERFORMED LEAK CHECK OF RT FUSELAGE AIR BLEED DUCTS IAW AMM 36-00-00-700-805 R & R O-RINGS AT LOCATIONS 4 AND 20 IAW AMM 36-11-10. PERFORMED LEAK DOWN CHECK OF RT SYS AGAIN LEAK CHECK AND ALL OPS CHECK GOOD.