What was found
DURING DESCENT & STARTING APU, BUS CTRL 2 FAIL CAS MESSAGE CAME ON. BUSS CONTROL SWITCH ON PANEL SWITCHED TO EMERGENCY AUTOMATICALLY WHILE OTHER ASSOCIATAED CAS MSGS. APU ABORTED START SEQUENCE AUTOMATICALLY. RT AVIONICS LOST POWER & EICAS ONLY DISPLAY LT INFO. COMPLIED WITH BUSS CONTROL FAIL CHECK LIST & LANDED UNEVENTFULLY. STARTED BOTH ENGINES & SHUTDOWN APU. RESTARTED APU & NO FAILURES NOTED BUT APU SLOW TO START WITH A HIGH AMP DRAW. SHUTDOWN APU & RESTARTED ACFT IN AIR MODE & BOTH ENGINES RUNNING. NO ELECTRICAL FAILURES OCCURED BUT APU ONCE AGAIN STARTED SLOW & A HIGH AMP DRAW ON RT BUSS. SHUTDOWN ENGINES & INSPECTED APU STARTER. FOUND APU STARTER POSITIVE TERMINAL LOOSE, BURNED, & MELTED SOLDER ARO