As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED "ABNORMAL NLG INDICATION AFTER T/O - RED AND GREEN ANNUNCIATORS ILLUMINATED AFTER RETRACTION." CREW RETURNED TO PHX AND LANDED WITHOUT FURTHER EVENT. MAINTENANCE REMOVED AND REPLACED THE NLG DOWN POSITION SENSOR, S845, IAW BOEING 737-300 MM 32-51-61. ALSO, REPLACED THE NLG DOWN SWITCH CARD M01214 AND THE NLG LOCK PROX SWITCH CARD M01215 IAW BOEING 737-300 MM 32-9-20.