As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - Flt 3659 - Crew reported that on approach the nose gear unlock indication flashed on and off with a loud banging noise heard. The aircraft landed at IAH without incident. Maintenance removed and replaced the proximity switch and the proximity switch electronic unit. The aircraft was returned to service and the problem re-occurred on the same date, flight 3329. Maintenance performed an adjustment of the nose landing gear proximity switch and the aircraft was approved for return to service.