What was found
AFTER TAKEOFF, GEAR WOULD NOT RETRACT, SYSTEM 2. SWITCHED TO SYSTEM 1 AND GEAR RETRACTED. CAUSED LOSS OF ADC 2, ALL PITOT HEAT, CABIN REGULATOR 2, AUTOTHROTTLES, AUTOPILOT 2. COULD NOT RECOVER ANY OF IT. FOUND PEU WITH SEVERAL FAULTS FOR FAILED PROXIMITY ELECTRICAL UNIT. RT & PROXIMITY ELECTRONIC UNIT IAW AMM 32-31-71-04. OPS CHECKED NORMAL, NO FAULTS NOTED. JACKED ACFT IAW AMM 07-11-00-00. PERFORMED NORMAL EXTENSION AND RETRACTION OF LANDING GEAR, NR 1 AND NR 2 SYSTEMS SEVERAL TIMES, EACH WITHOUT ANY FAULTS. GEAR EXTENDS AND RETRACTS NORMALLY IAW AMM 32-31-00-05. REMOVED ACFT FROM JACKS IAW AMM 07-11-00-00. ACFT NOW IN NORMAL GROUND CONFIGURATION.