What was found
CABIN PRESSURE FLUCTUATED AT ALL ALTITUDES, CABIN CLIMBS & DESCENDS 4000 PSI, DIVERTED FOR REPAIR. MX TROUBLESHOT CABIN PRESSURE SYS & REPLACED AFT OUTFLOW VALVE. AFTER INSTALL OF NEW OUTFLOW VALVE A NEW FAULT OCCURRED, CABIN PRESSURE CONTROL INOP IN AUTO. MX ISSUED MEL 21-14. AUTO CABIN PRESSURE SYS INOP & MX FERRIED ACRFT. MX REPLACED AFT OUTFLOW VALVE IAW BMM, OPS CHK GOOD. CONFIRMED REASON FOR REMOVAL, UNIT FAILED PARA 7 BONDING RESISTANCE CHK. CLEANED MATING SURFACE FOR EBOX 2 & REACCOMPLISHED TEST, UNIT PASSED PER CMM. FUNCTIONAL TEST OF OUTFLOW VALVE ALSO FAILED EBOX TESTING. EBOX 1, C2 (CAPACITOR) FOUND LEAKING ON POWER SUPPLY BOARD, CAPACITOR REPLACED & BOARD CLEANED.