The current comes from the floppy connector. One line is burnt out coming from the floppy connector. Can be seen on the other side of the board.
Just crazy. I plugged it in the first time and then it starts smoking immediately!
It's like AMT just cobbles up random components and have their fingers crossed that the customer gets it working. If they had tested this before it shipped, the backplane would have already been installed on the unit prior to shipping.
I had 3 boards on my system when I plugged it in. The other 2 boards were damaged in shipping. However, I couldn't get the back plane to align with all 3 boards, so I just tries with 2 boards.
Well.... backplane apparently is fried.
No wonder Bitmine has an entirely new revision of the backplane.
Meanwhile, AMT still owes me $6000 despite delivery. You can't sell none working product and claim delivery. What I have is a 48 pound brick.
By the looks of the photo, and the apparent results, it seems that another board was also damaged, though you may not have seen it. Looks like it shorted-out, possibly on the heat-sink. That, or a trace was broken, which caused a regulated component to fail, pulling more amps than it should have. What should be of concern, is that the PSU should have detected the short, and turned-off.
In any event, it looks like that line needs to be thicker. I can see that the through-holes consume a great volume of the trace connection itself. Those should have been designed offset, like a "T", not inline. Short fix for that trace, if there is an issue with it being too thin, is to solder jumpered wires into the through-holes, to double-up the amperage ability in that line. (That, or scrape off the enamel, and run a length of solder over the entire trace. Which would then have to be re-enameled.)
I would assume that all boards were damaged, not just the three you saw physical damage on.
