What was found
LEVEL AT FL 290 WITH ENGINE AND AIRFOIL ANTI-ICE ON, CREW FELT A PRESSURE BUMP AND NOTICED CABIN ALTITUDE CLIMBING AT 1500 FPM. CYCLED PRESSURE CONTROLLERS FROM AUTO TO MANUAL AND BACK, ANTI-ICE SWITCHED OFF, BUT CABIN STILL CLIMBED. INITIATED RAPID DESCENT TO FL 140; CLEARED WITH ATC. FLIGHT CREW DONNED O2 MASKS AND PERFORMED COM PROCEDURES. CLEARED TO 10,000 FT FOR REST OF FLIGHT. CABIN MAXED OUT AT 10,500 FT MSL. MASKS DID NOT DEPLOY AND LANDING WAS UNEVENTFUL. MAINTENANCE RECONNECTED A BLOWN BOOT ON LT ACM AND RETURNED AIRCRAFT TO SERVICE.