Picked this console up today (fixed it) -
Can't 100% say what went wrong with it, potentially a knock in transit? 2 Capacitors that were near the usb end of the demon (Y1/3/5) were hanging on for their lives. (see image)
Obviously the console could r/w the stock nand as that's one of the basic tests that I do before sending a console out! E71 was being caused by a bad block (nanddump1 on demon/stock replicated this but XeLL still booted) - The same bad block was causing issues on the new RGH image we tried over TeamViewer.
I've lifted the demon and QSB, refitted the offending capacitors, refitted a new corona QSB, rebuilt a stock nand and flashed this to 360/demon (both boot) and then rebuilt an RGH image from this dump and tested it on both banks - All working 100%.
Demon can interface with the console nand again just fine. Will reassemble and have it shipped to lettucekl tomorrow for Tuesday delivery.