Yes, we've had 2T drives in our cases for about a year now, with no issues. Our 2T drives are rated at 0.5A on +5/+12, while the 3T drives are rated at 0.75A, so we're suspicious of this difference.
(For what it's worth, the datasheet for the MOSFETs used are rated at 6A; it's possible the manufacturer got it mixed up with the 0.6A batch of MOSFETs. I don't have any hard evidence though, so I'd rather not post speculation.)
lold hard. transistors are not resistors. peak current is not just a variable parameter.
I suppose this was due to bad contact somewhere (socket or HD) and transistors working in linear mode for more time than they can withstand, overheating and boom...
EDIT: or may be they used a crappy hotswap controller (if they actually used one) which cannot pump enough current into gates of those mosfets.
Er, I should say "tested at 0.6A" MOSFETs. If they have thin bond wires or something, it's plausible that excess current just vaporized them. If they never tested them at 6A, and skimped on the gauge...
I also saw a couple instances where the trace to the gate blew up (like, black board, no copper, looks like a burnt fuse), so it's possible that static during manufacturing killed their FETs even before they shipped. (We're pretty good about static, and if it was our fault I think maybe one drive/channel would die, not several)
yes, that would be better. in reality parameters of transistors vary. but when it is off by an order of magnitude these parts (and actually the whole batch) go to trash.
> trace to the gate blew up
if it really was trace to the _gate_ then it might be blown after mosfet itself melted. Because even really fat FETs (with high gate capacity, D-S rated to hundreds of amperes) cannot do this to copper trace.
(For what it's worth, the datasheet for the MOSFETs used are rated at 6A; it's possible the manufacturer got it mixed up with the 0.6A batch of MOSFETs. I don't have any hard evidence though, so I'd rather not post speculation.)