B737-300 CREW ENCOUNTERED AIR-GND LOGIC SYS FAILURE.

Narrative

DAY VFR FLT; CAPT FLYING. CREW ENCOUNTERED CONTINUING AND MULTIPLE PROBS FROM LIFTOFF TO FL230. AUTOTHROTTLES DISENGAGED (NO WARNING LIGHT); VERT NAV WOULD NOT ENGAGE; LATERAL NAV WOULD NOT ENGAGE; XPONDER WAS INTERMITTENT. BOTH CAPT'S AND FO'S EADI AND EHSI BEGAN TO FLICKER. THE ELECTRONIC EQUIP SUPPLY FAN FAILED (SWITCHED TO ALTERNATE). APPROX 80 MI W OF FOD; THE CABIN ALT WARNING HORN CAME ON AND THE CABIN ALT INDICATED JUST OVER 10000 FT. QRC FOR CABIN DEPRESSURIZATION DID NOT CTL PRESSURIZATION. AN EMER DSCNT WAS INITIATED WITH THE QRC. DECLARED EMER AND DSNDED TO 10000 FT. FLT ATTENDANTS INDICATED NO INJURIES OR PAX DISTRESS. COORD WITH DISPATCH AND MAINT CTLR. FUEL WAS NOT A FACTOR AND THE ACFT WAS IN GOOD SHAPE OTHER THAN PRESSURIZATION AND PREVIOUSLY NOTED PROBS. ACFT CONTINUED TO ORD WITH ASSUMED MALFUNCTIONING AIR-GND LOGIC. FLT COMPLETED TO ORD AT 10000 FT. NORMAL LNDG COMPLETED. NO FURTHER INCIDENT. NO PAX INJURIES OR COMPLAINTS. CREW WAS BEING ADMINISTERED AN FAA LINE EVALUATION. AT THE TIME; DEBRIEF AT COMPLETION OF FLT; FAA INDICATED THE CREW DID AN EXCELLENT JOB. DEBRIEFED FLT MGR AND UNION. SUPPLEMENTAL INFO FROM ACN 551562: REQUESTED EMER VEHICLES TO BE AVAILABLE UPON LNDG. SUBSEQUENTLY LANDED THE ACFT WITHOUT FURTHER INCIDENT. I BELIEVE THERE WAS A FAILURE IN THE AIR-GND LOGIC SYS.