What was found
ON GEAR RETRACTION NR 2 GEAR POSITION SYS DEFAULT WITH NOSE GEAR UNSAFE INDICATION. NOSE GEAR NR 1 SYS WAS NORMAL. SWITCHED FROM NR 1 TO NR 2 BAND BACK TO NR 1 SYS. NOSE GEAR ON NR 2 SYS REMAINED UNSAFE. EMERGENCY DECLARED. FOUND NOSE GEAR UPLOCK SWITCH 36-GB FAULTED. T/S WITH TECH SERVICE SUPPORT DETERMINED ACFT WIRING OK. PROBLEM IS WITH SWITCH. R & R SYS SWITCH IAW AMM 32-31-20; SUB 32-31-20-410-010 A 01 AND 32-31-20-410-011. PERFORMED NOSE GEAR SWING IAW INDICATING AND WARNING TEST IAW AMM 32-61. OPS GOOD.