What was found
ON APPROACH INTO KSBA FROM KBUR, THE CREW SELECTED GEAR DOWN AND THE GEAR DID NOT EXTEND ALONG WITH A GEAR UNSAFE LIGHT. THE CREW ALSO NOTICE THE LANDING GEAR CIRCUIT BREAKER TRIPPED. THE CREW CONTACT KSBA TOWER TO DISCONTINUE APPROACH AND ELECTED TO RETURN TO KSBA. AFTER COMPLYING WITH THE LANDING GEAR MANUAL EXTENSION ABNORMAL CHECKLIST, THE CREW LANDED AT KSBA WITHOUT INCIDENT. MAINTENANCE PERFORMED AN OPERATIONAL CHECK OF THE LANDING GEAR SYSTEM AND FOUND A DEFECTED POWER PACK. MAINTENANCE REMOVED AND INSTALLED A SERVICEABLE POWER PACK. THE OPERATIONAL CHECK OF LANDING GEAR SYSTEM PERFORMED NORMALLY AND THE AIRCRAFT WAS RELEASED AND RETURNED TO SERVICE.