| The LSI card probably blew its fuse. LSI seems to be unique in putting a fuse in series on the power input of some of its PCIe cards, which is a non-standard implementation for a PCIe card design. The fuse on the LSI card is sized too low and may sometimes blow at the inrush current the LSI card demands at power up. (In the PCIe specification, it is not the responsibility of the system to limit the inrush current to the card.)
The fuse could have been omitted; it was not. The fuse could have had a higher rating; it did not. The fuse could have been a slow-blow type; it was not. The fuse could have been user replaceable; it is not. The fuse could have been a resettable type; it is not.
From our resellers, we have heard anecdotes of LSI cards blowing their fuse in some systems and not others, apparently depending on how fast the 12V power comes up. Power would generally come up slower in a server in which the motherboard places a low-impedance demand on the power supply. In Thunderbolt expansion chassis, there is no motherboard to draw power, and the power supply voltage comes up rather quickly. This is LSI's issue to solve. |