Ok, so I checked it against the page mentioned before and as far as I can see, everything is connected right including the heater wires (I have been through the entire build guide and checked absolutely everything). First question, should the display and the blue LED on the print head light up when it is connected to ONLY the mains power? Currently, they both light up only when connected to both mains and USB. Secondly, to elaborate on my previous problem, the controller screen starts to flicker and go off after the heating has failed. Does this mean the problem is with mains power not getting through or could it be a different problem? I have also tried everything with the power switch in both positions just to make sure the guide telling me to flick the switch towards the cable connections is right. Again, I look forward to hearing any suggestions from anyone with the knowledge who is kind enough to help! :-)