What was found
FLT 1835 - DURING CRUISE AT FL270, A PRESSURIZATION FAILURE AS CABIN ALTITUDE WARNING HORN SOUNDED. DECLARED AN EMERGENCY & DESCENDED TO 10,000 FT. ACCOMPLISHED QUICK REFERENCE PROCEDURES & REGAINED CABIN PRESSURE. FLT CONTINUED & LANDED AT RSW WITHOUT FURTHER INCIDENT. ACCOMPLISHED PRESSURIZATION TROUBLESHOOTING & CARD & FOUND LT PACK SYS LOW FLOW MODE & CABIN PRESSURE LEAK TEST FAILED. R&R LT ENGINE HIGH STAGE VALVE PER MM 36-11-85. CHKD LT PACK LOW FLOW MODE & PRESSURE LEAK TEST. CHECK PASSED. R&R CABIN PRESSURE CONTROLLER.