What was found
AFTER T/O CABIN WILL NOT PRESSURIZED AND LEFT PACK OFF WITH THE SWITCH PRESSED ON,STAYED BELOW 10000. QRH WAS PREFORMED DIDN€™T FIX IT. (FLIGHT 5397 - FILED CLOSED) FOUND LEFT 10TH STAGE SOV NOT TO BE OPENING WHEN SELECTED REMOVE AND REPLACED LEFT 10TH STAGE SOV AND FOUND BACK SHELL ON CANNON PLUG BACKED OFF TIGHTENED BACK SHELL AND PREFORMED OPS CHECK PER CRJ 200 AMM 36-11-04 OPS CHECK GOOD. / PREFORMED OPS CHECK OF CABIN PRESSURIZATION PER CRJ 200 AMM 21-30-00 OPS CHECK GOOD.