My thought was that even though it was the Norco hardware that was blowing out, it could be the 3T drives are the thing that are somehow exceptional. Their rated current is 0.75A, but what do they draw and for how long in the initial power on surge?
Well, there are a couple of surges not dealt with here. The first and likely highest current spike is the charging of all the capacitance in the hard drive. I've never looked but I would imagine the motor driver circuit and the electronics have fairly large capacitors on the input power rails. This should be relatively short lived but higher Rds from a crappy MOSFET would increase the charging time. The second is everything powering on, there are likely secondary regulators for the electronics (probably needs 1.8 or something not 5 or 3.3) and they could be regulating the 12V rail to something more controlled for the spindle motor as well. Those switchers coming online and charging capacitors on the output side will cause a bit of a spike also. Then there is the spike from firing up the spindle motor and the head servo, likely not insignificant. I have no idea if there is an inrush current / duration limit in the SATA/SAS spec or not, I would think so but I've never seen a drive manufacturer quote these numbers.
