I have 2 of these. I actually had to return one to Amazon seller because I couldnt get more than 45ghs from it. Also dumped the original USB because not 1 of them worked on Linux for some reason. Chopped the PSU barrel pin and connected to dedicated 450W PSU both on separate channels. Running on Ubuntu

I use cgminer 4.9.0 compiled just for iccarus and I cant get these to run longer thatn 24 hours, ever. They go stable, stable, stable, ok I go to bed now. In the morning ZOMBIE.
I got to go unplug the USB, power down, kill cgminmer, plug in power, USB cables and start cgminer. Starts mining again. Then next morning the same problem.

Very rarely one or the other goes zombie. I keep mine cold room ambient 5 degrees with other NAS'es and stuff. So when they running for a few hours the heat sinks are hardly 40 degrees.

Do I need MORE cooling?

I think this is a USB controller / or firmware issue. Because if I power down without removing USB the red light still shines inside and power up and restart cgminer it does NOT find the device. So if the firmware still runs on USB power maybe its firmware crashing, I am not sure. But I was wondering why the bitmain official guide specifically says to plug POWER IN FIRST then USB. It shouldn't matter. (I actually got mine mining 7ghs just off USB power, lol - That was wierd? Plugged in power and jumped to 63ghs)

There must be a firmware issue on these devices I cant believe Bitmain did not pick up on this, they never tested a single unit longer than 24 hours?? Not sure about Windows but maybe its a Linux specific problem?