What was found
TPA - FLT 2674 - ON CLIMB-OUT, NR 2 MACH METER OFF FLAG DISPLAYED, NR 2 ALTIMETER STANDBY FLAG APPEARED, TCAS BECAME INOPERATIVE, ALT REPORTING ON THE XSPONDER BECAME INOP, NR 2 V-SPEED SHOWED A DESCENT DURING CLIMB. CREW UNABLE TO PULL ANY CB'S ON PANEL TO RESET SYS, ABLE TO GET INSTRUMENTS BACK ON LINE FOR A FEW MINUTES, FAILED AGAIN. CAPTAIN'S GLIDESLOPE ON MEL AT THE TIME. FLT RETURNED, LANDED WITHOUT INCIDENT. NO EMERG DECLARED. MAINT REMOVED AND REPLACED NR 2 AIR DATA COMPUTER. PERFORMED PITOT STATIC TEST, ALL INDICATIONS NORMAL. PERFORMED SATISFACTORY CHK OF AIR DATA COMPUTER SYS. CLEARED MEL ON GLIDESLOPE BY REMOVING AND REPLACING NR 1 NAV RECEIVER. (PN 2041234-3422). (X)