Thanks for the thread. Just had the same issue happen to me on iGen4 and it was the breaker that was tripped.
I just got the same faults that wouldn't clear. Turned out to be a bad thermistor on the top heat roller. Switched it out and press working again.
Ever have any luck with this? Ive been getting the same fault 3307 off and on for a while now, and usually a reset would take care of it. But...