Todd I have the exact same issue with my i7 8GB RAM SP3. my external blu-ray drive connects then disconnects every 5 seconds, my 1TB lacie USB POWERED ONLY without Y cable external drive does the same thing, my EXTERNAL 12V 2A powered 3TB lacie hard drive
array connects and works however after 30 seconds it spins down and "goes to sleep" but stays connected to my surface pro 3, still showing up in my computer. if i try accessing it, it has to wake up the drive first. I have a WD USB 2 powered drive that stays
connected but also goes to sleep the same as my other 3TB drive and even when I use a Y cable to the surface pro power pack or powered USB hub the drives that connect and disconnect still do not function. finally I have a Samsung Galaxy S5 and I can not use
that with this machine either as it does the exact same thing so i have to use wifi to sync data. I have a SP3 USB3 to Ethanet adaptor and that too connects and disconnects every 20 seconds.
I put it down to USB port gives out only 500ma or less and also does not have the correct data bandwith.!
I have contacted Microsoft so many times but the geeks don't seem to know "what i'm on about, never heard of this before, i'm the only customer to ever report it, do updates,go try this (never works" then they stop responding.! Im about to smash this machine
out of my window.! I am in the process of getting them to give me a free surface pro 3 Doc to solve these problems it is my right under consumer law.
So frustrated.. :(