Narrative:

Climbing from FL300 to FL340; the cabin altitude warning horn sounded. First officer was flying and silenced the horn. The cabin was climbing at 1000 FPM. I hit the altitude hold and turned the pressure controller to manual. The cabin altitude climbing stopped. I told center we were having pressurization problems and were descending to FL300. First officer started down while we assessed the problem. Before we got to FL300; I asked to continue to FL280. After the controller was in manual; the pressurization was under control. Both packs and bleeds were in their normal position with normal pressure. The outflow valve gauge showed closed. We went through the QRH items. No masks dropped. First officer called dispatch and talked to maintenance and they told us to contact maintenance. We ACARS'ed maintenance control and got an ACARS from dispatch asking if we did an emergency descent and what altitude we were at. We did not need to do an emergency descent since the pressurization was under control. Next; dispatch changed our destination to ZZZ and then asked if we were ok at FL280 and if we were a non emergency. There was no emergency at that time. Center turned us back to the arrival to ZZZ and descended us to FL270 for direction. I told the passenger we had a pressurization problem and were returning to ZZZ. We controled the pressurization in the manual mode back to ZZZ. Fix the problem from the day before when the same problem occurred on this aircraft.

Related reports:

Google
 

Original NASA ASRS Text

Title: A B737-300 FLT CREW EXPERIENCED LOSS OF CABIN PRESSURE IN CLIMB ABOVE 30000 FT. THEY REGAINED CONTROL USING THE MANUAL CONTROLLER.

Narrative: CLBING FROM FL300 TO FL340; THE CABIN ALT WARNING HORN SOUNDED. FO WAS FLYING AND SILENCED THE HORN. THE CABIN WAS CLBING AT 1000 FPM. I HIT THE ALT HOLD AND TURNED THE PRESSURE CONTROLLER TO MANUAL. THE CABIN ALT CLBING STOPPED. I TOLD CTR WE WERE HAVING PRESSURIZATION PROBS AND WERE DSNDING TO FL300. FO STARTED DOWN WHILE WE ASSESSED THE PROB. BEFORE WE GOT TO FL300; I ASKED TO CONTINUE TO FL280. AFTER THE CONTROLLER WAS IN MANUAL; THE PRESSURIZATION WAS UNDER CTL. BOTH PACKS AND BLEEDS WERE IN THEIR NORMAL POS WITH NORMAL PRESSURE. THE OUTFLOW VALVE GAUGE SHOWED CLOSED. WE WENT THROUGH THE QRH ITEMS. NO MASKS DROPPED. FO CALLED DISPATCH AND TALKED TO MAINT AND THEY TOLD US TO CONTACT MAINT. WE ACARS'ED MAINT CTL AND GOT AN ACARS FROM DISPATCH ASKING IF WE DID AN EMER DSCNT AND WHAT ALT WE WERE AT. WE DID NOT NEED TO DO AN EMER DSCNT SINCE THE PRESSURIZATION WAS UNDER CTL. NEXT; DISPATCH CHANGED OUR DEST TO ZZZ AND THEN ASKED IF WE WERE OK AT FL280 AND IF WE WERE A NON EMER. THERE WAS NO EMER AT THAT TIME. CTR TURNED US BACK TO THE ARR TO ZZZ AND DSNDED US TO FL270 FOR DIRECTION. I TOLD THE PAX WE HAD A PRESSURIZATION PROB AND WERE RETURNING TO ZZZ. WE CTLED THE PRESSURIZATION IN THE MANUAL MODE BACK TO ZZZ. FIX THE PROB FROM THE DAY BEFORE WHEN THE SAME PROB OCCURRED ON THIS ACFT.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.