What was found
DURING PREFLIGHT FOUND ALT EXT CONT C.B. FOUND POPPED. T/S PER AWDG 32-35-11. WITH C/P DISCONNECTED ON HYD PRESSURE SWITCH IN NOSE WHEEL WELL. C/B STAYS IN. NIS ON PRESSURE SWITCH. AMM: 32-35-51-4 PRESSURE SWITCH S10366 CONNECTOR D4360 JUMPERED CONTACTS 2 AND 3 AND CIRCUIT BREAKER IMMEDIATELY POPPED. AFTER OPENING GEAR DOORS CIRCUIT BREAKER WILL NOW REMAIN CLOSED. ANY ATTEMPT TO RAISE LANDING GEAR DOOR RESULTS IN THE ALT POWER PACK REMAINING ENERGIZED AND THE DOORS NOT CLOSING. AMM: 32-35-10-4 AMM: 32-35-00-5 R & R'D ALTERNATE EXT SYS POWER PACK PER ABOVE AMM. UNIT CHANGED AS PRECAUTIONARY. LANDING GEAR ALTERNATE EXTENSION ADJ/TEST NORMAL PER ABOVE AMM. TERMINATING ACTION ACCOMPLISHED FOR EA F-3230-T0385724 AT 76,974:30 HOUR(S), 29,191 CYCLE(S) SWPM: 20-30-21 ASM: 32-30-01 WDM: 32-12-12 FOUND WIRE W2516-2520R SHORTED TO SHIELD SHORT DISTANCE FROM SPLICE SP1246 IN RH WHEELWELL. REMOVED DAMAGED SECTION OF WIRE AND CRIMPED NEW SPLICE SP1246 IAW B757 SWPM 20-30-21. LANDING GEAR ALTERNATE EXTENSION TESTS NORMAL IAW AMM 32-35-00-5. ACFT OKAY FOR SERVICE.