As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 7842, GSO TO IAD. ON TAKEOFF THE CREW REPORTED THAT THE PRESSURIZATION SYSTEM WAS NOT WORKING PROPERLY. THE CREW LEVELED OFF AT 10,000FT WITH ZERO CABIN ALTITUDE, ZERO DIFFERENTIAL PRESSURE, AND ZERO CABIN RATE OF CHANGE. THE QRH WAS FOLLOWED AND THE CREW SWITCHED TO MANUAL MODE AND THE CABIN ALTITUDE WENT TO 8,200FT. THE AIRCRAFT RETURNED TO GSO AND LANDED WITHOUT INCIDENT. THE AUTO PRESSURIZATION MODE WAS DEFERRED AND THE AIRCRAFT WAS RETURNED TO SERVICE. THE MEL WAS CLEARED IN CMH ON 8/5/2009 WHEN THE ELECTRO PNEUMATIC OUTFLOW VALVE WAS REPLACED.