What was found
ALB - FLT 4723 - UPON ARRIVAL WHEN CREW SELECTED GEAR HANDLE DOWN, HYD PUMP OPERATED BUT INTRANSIT LIGHTS STAYED ILLUMINATED AND THE GEAR FAILED TO EXTEND. FLT CREW FOLLOWED CHECKLIST, FOUND CIRCUIT BREAKER F-7 (HYD LANDING GEAR CONTROL) TRIPPED. CREW RESET C/B ONCE AND IT TRIPPED IMMEDIATELY. CREW THEN FOLLOWED CHECKLIST FURTHER WHICH LED TO RECYCLE THE GEAR HANDLE. RECYCLING GEAR HANDLE UNSUCCESSFUL. CREW FOLLOWED CHECKLIST TO PULL THE EMERG LANDING GEAR HANDLE. LANDING GEAR EXTENDED AND ACFT LANDED WITHOUT INCIDENT. MAINT FOUND THE L/G SELECTOR VALVE AT FAULT. MAINT REPLACED THE L/G SELECTOR VALVE ALONG WITH THE EMERG GEAR EXPLOSIVE BOLTS AND PERFORMED ALL SYS CHECKS. ACFT RETURNED TO SERVICE. (X)