As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NOSE GEAR RELEASED FROM LOCK IN FLIGHT CLIMBING THROUGH FL 280 AND FL 320 AND DESCENDING THROUGH FL 230. GEAR DID NOT EXTEND, NOR DID NOT OBSERVE THE GEAR UNLOCK LIGHT. PERFORMED GEAR BUMP TROUBLESHOOTING IAW CESSNA 750 MM 32-30-00. FOUND NOSE GEAR UPLOCK SWITCH OUT OF ADJUSTMENT. ADJUSTED NOSE GEAR UPLOCK SWITCH IAW CESSNA 750 MM 32-30-05. PERFORMED MULTIPLE GEAR SWINGS AFTER SWITCH ADJUSTMENT SYSTEM, CHECKS GOOD AT THIS TIME.