Just had a rather odd situation occur...
One of my B1 S3s, running latest firmware decided to go beep crazy. Normally I'll get a beep or two and it'l stop, but this time it wouldn't.
Syslog showed the following:

Sat Aug  2 07:48:19 2014 kern.err kernel: [ 6774.600000] usb 1-1: clear tt 1 (9041) error -71
Sat Aug  2 07:48:19 2014 kern.err kernel: [ 6774.610000] usb 1-1: clear tt 1 (9041) error -71
Sat Aug  2 07:48:19 2014 kern.err kernel: [ 6774.620000] usb 1-1: clear tt 1 (9041) error -71
Sat Aug  2 07:48:19 2014 kern.err kernel: [ 6774.710000] usb 1-1: clear tt 1 (9041) error -71
Sat Aug  2 07:48:19 2014 kern.err kernel: [ 6774.720000] usb 1-1: clear tt 1 (9041) error -71
Sat Aug  2 07:48:19 2014 kern.err kernel: [ 6774.730000] usb 1-1: clear tt 1 (9041) error -71
Sat Aug  2 07:48:20 2014 kern.err kernel: [ 6774.830000] usb 1-1: clear tt 1 (9041) error -71
Sat Aug  2 07:48:20 2014 kern.err kernel: [ 6774.840000] usb 1-1: clear tt 1 (9041) error -71

Sat Aug  2 07:48:20 2014 kern.err kernel: [ 6775.410000] hub 1-1:1.0: cannot reset port 1 (err = -71)
Sat Aug  2 07:48:20 2014 kern.err kernel: [ 6775.420000] hub 1-1:1.0: cannot reset port 1 (err = -71)
Sat Aug  2 07:48:20 2014 kern.err kernel: [ 6775.420000] hub 1-1:1.0: cannot reset port 1 (err = -71)
Sat Aug  2 07:48:20 2014 kern.err kernel: [ 6775.510000] hub 1-1:1.0: cannot reset port 1 (err = -71)
Sat Aug  2 07:48:20 2014 kern.err kernel: [ 6775.510000] hub 1-1:1.0: cannot reset port 1 (err = -71)
Sat Aug  2 07:48:20 2014 kern.err kernel: [ 6775.520000] hub 1-1:1.0: Cannot enable port 1.  Maybe the USB cable is bad?

Issued a reset to CGMiner and it came back online, but anyone out there have any ideas what might have caused a USB issue on these? In theory it shouldn't be possible, as the whole USB infrastructure is on the mainboard (no loose plugs or anything).