Please people put a smoke detector near your mining equipment. I had just seen this.
And its still ticking away.
I had that happen to me, too, but not nearly that bad. Caught it in time.
The fuse did not blow, but the plastic of the fuse melted away and glued itself to the board.
I couldn't remove the fuse without using Vice-Grips to grab what's left of the plastic and carefully work it free. Then I was left with bare metal tabs sticking out of the fuse holder. Removed these carefully, with needlenose pliers.
The lid on the USB hub comes off easily by turning those little screws. An Allen wrench, 3 mm size, worked perfectly for me. It is much easier to access the fuse holder, and ATX power supply connector, this way. Don't try removing the fuse (or whatever's left of it) without removing the lid first.
Reason is, when you're working on removing the fuse, be sure not to move or otherwise put stress on the fuse holder block! It's soldered there with some very thin solder joints (probably too thin, that also causes it to overheat even more). It's a fragile, weak area. Might be a good idea to support the fuse holder block so that it can't move, perhaps with another pair of pliers, while you work at digging out the burned fuse.
Although my power supply claims to be "500 watts", it is only rated for 30 amps on the 5 volt rail (150 watts). With 49 Erupters installed, I'm right on the edge.
I replaced the 40 amp fuse, that melted away, with a 30 amp fuse. It has less capacity, but all 49 Erupters have been mining for several days now, and it has not blown yet. I recommend doing this. It also matches what my power supply is rated at, which will help keep it from accidentally becoming overloaded.
The fuse plastic is also a bit thinner, so it will stand away from the board a little bit, and hopefully make for an easier job of removing it later, if necessary. The supplied 40 amp fuse that comes with the USB hub might be made out of a weak plastic that melts easily, it would seem. My new fuse is nowhere near melting.
I also concentrated my fan cooling on blowing directly on the fuse area! That area is a critical weakness and it gets hot.
Also the ATX power supply connector. Feel it, and one of the wires will be warm to the touch. That's the 5 volt wire. The 24-pin Molex connector also doesn't like heat. Molex is known to blacken easily, as anybody who has owned a pinball machine will tell you
When Molex blackens, it doesn't feed power as easily, so it blackens more, etc. and eventually you get thermal runaway and it burns.
On the other hand, the Erupters themselves don't really mind getting hot. They still work fine. Before I got this big hub, I just had the Erupters sitting on my desk in ordinary little consumer USB hubs, without cooling, and they seem to be OK (although very wam to the touch).
I re-aimed my big fan at this side of the USB hub, so it's blowing full blast on the fuse connector and ATX connector! The wind also has the nice side effect of blowing across the Erupters as well, from this angle, helping them stay cool. I recommend doing that, as you've seen, it's obviously most important to cool that area of the USB hub, with as much air as you can get blowing directly on that fuse.
And definitely a smoke detector in the room
