I must agree! I was a long time believer (and perhaps still am) in DC drives. However, AC Drives have crossed so many milestones in the past several years that it's become hard to challenge their ability, efficiency, or integrity. But as far as troubleshooting goes...DC drives are much more simple. Of course many of todays drives are modular and don't even require an engineer or technician to replace them. Wahhh! hahahaha