Yeah, this could be caused by a faulty connection to the power supply.I'll bet this could have been solved by either a new supply or a simple resolder of the power jack. I'm sure Eventide would have helped guide you through it, too.
Since the pedal you purchased was used, I can only guess as to its history, but I've never had any problems with mine and there are many more that haven't had problems with theirs, either. If you want a plug'n'play/one-sound kind of pedal, maybe the MF isn't for you, but if you're looking for a versatile pedal that sounds killer, I'd recommend giving the MF another chance, but maybe a less abused example.
