What was found
PIT - FLT 202 - APPARENTLY THE RIGHT A/C BUS HAS AN APU RELAY STICKING WHICH WILL NOT ALLOW ANY OTHER POWER SOURCE TO POWER THE RIGHT A/C BUS. THIS OCCURS EVEN WITH THE APU SHUT DOWN. RESET CROSS-TIE RELAY. APU GEN SYSTEM INOP. TRANSFERRED DMI LOG NR 00712 IAW MEL 24-1-2 CAT C. REMOVED AND REPLACED RT AUXILIARY RELAY IAW DC-9 MM J24-20-6. PERFORMED A/C CROSS-TIE CHECK WITH ENGINES NR 1 AND NR 2 RUNNING. A/C CROSS-TIE CHECKS GOOD. OPS CHECK NORMAL IAW FCOM. CLEARED DMI NR 00712. PLACARD REMOVED AND DISPATCH NOTIFIED THROUGH MAINTENANCE CONTROL. (M)