This may not help but I'll throw it out there. When I first extended my Rift cables (all of them) I got random blackouts. I added an HDMI repeater between the 2 sections of the HDMI cable (extra 3m) and never had that problem since. So it could be a power issue. I don't know if the USB could be responsible too for yours, so try another USB port for the Rift or sensors if you haven't. I did get some errors from one of the 2 sensors, so moved to a different USB port, fine since. Thinking laterally, if it was the HDMI, you could try a repeater and add a short length of HDMI cable (making sure you get the right male/female connections).