MD80 CREW WAS UNABLE TO PRESSURIZE THE ACFT AFTER TKOF IN DFW CLASS B AIRSPACE.

Narrative

AIR INTERRUPT. DEPARTING DFW; FO WAS FLYING THE ACFT. SHORTLY AFTER TKOF; BOTH PACKS FAILED AND ACFT FAILED TO PRESSURIZE PROPERLY. PROC WAS FOLLOWED TO REINSTATE THEM TO NO AVAIL. (ACFT HAD A VERY RECENT HISTORY OF SIMILAR PROB.) I TOOK OVER FLYING DUTIES; ADVISED ATC THAT WE HAD A PRESSURIZATION PROB. THEY GAVE US 345 DEG HDG; MAINTAIN 5000 FT. I ALSO REQUESTED FO TO ATTEMPT MANUAL CTL OF OUTFLOW VALVE. HE RPTED MANUAL WAS INEFFECTIVE. IT FELT LIKE IT WAS HANGING UP ON SOMETHING. WHILE THIS WAS GOING ON; I NOTICED THAT THE CAPT IVSI HAD FAILED FOR ABOUT 5-6 MINS. I ALSO OBSERVED A MOMENTARY FLAG ON THE CAPT'S AIRSPD INDICATOR. I ADVISED ATC THAT WE WERE FINE; BUT WE WERE RETURNING TO DFW BECAUSE OF A PRESSURIZATION PROB. NO EMER WAS DECLARED. I REQUESTED THE FO TO CONTACT DFW OPS TO ADVISE DISPATCH AND MAINT OF OUR RETURN TO BASE. I ADVISED FLT ATTENDANTS AND MADE A PA ADVISING OUR PAX. WE COMPUTED WT; RWY REQUIREMENT; AND LNDG SPDS FOR AN OVERWT LNDG AT DFW. LANDED UNEVENTFULLY AT 141000 LBS. VERY SMOOTH LNDG -- 100-200 KTS VERT SPD; ROLLED OUT WITH VERY MINIMAL BRAKING RETURNED TO GATE; MADE APPROPRIATE LOGBOOK ENTRIES FOR PRESSURIZATION PROB AND OVERWT LNDG. WE OBTAINED ANOTHER ACFT AND DEPARTED FOR LAX.