My last U3 just died. I can see it with zadig and reinstall the driver, but it does not get recognized by cgminer, nor is the R1 able to fire it up as a controller. The red USB led lights up, but that's it. It will no longer hash no matter what I do. RIP U3.
Yours may just be dead/defect also, zOU.
And as usual it's never the users fault and bitmain sent you a crappy u3 right?
I don't want to say it's your fault but chances are you overclocked it behond safe parameters even though you might not admit it.
I have 3 out of 3 working fine with my R1. I am not trying to push them though. I get around 50GH or so out of each and around 150GH or a tad less out of all together. So far has seemed to work pretty good.
I don't really OC anymore on any of my miners. During S3 day's I didn't have a second thought about doing it. But i just don't risk it anymore besides my compacs I do push them sometimes.