As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INVESTIGATED RED WARNING LIGHT ILLUMINATED IN LANDING GEAR CONTROL HANDLE WITH LANDING GEAR DOWN AND LOCKED. FOUND NLG DOWNLOCK SWITCH. S508 INOPERATIVE PN 101-3646289, MICROSWITCH-FREEPORT PN 1CH25. REPLACED SWITCH AND ADJUSTED IAW MM. LANDING GEAR POSITION/WARNING SYSTEM FUNCTIONAL TESTS NORMAL. (K)