What was found
(CAN) DURING A TRAINING FLIGHT THE INVERTER FAILURE NR 2 WARNING LIGHT CAME ON. AT APPROXIMATELY THE SAME TIME SMOKE WAS DETECTED IN THE CABIN. EMERGENCY WAS DEALT WITH IAW THE CHECK LIST. AFTER LANDING AT MAINTENANCE FACILITY, THE AME QUICKLY DETERMINED THAT THE NR 2 INVERTER HAD FAILED. BURN MARKS ON THE OUTER CASE & A STRONG ODOR OF BURNED METAL/PLASTIC WAS DETECTED. NR 2 INVERTER WAS REPLACED WITH SERVICEABLE UNIT AND NO FURTHER FAULT WAS DETECTED.