hi all just wanted to pass on that I have the universal ramps 1.4 kit working on a single 24v 400 watt ps. this is a really nice kit. I see others might be having issues. I must have been lucky. no diode touching to get turino/ramps 1.4/heatbed mk2a/motor drivers working on 24. just plugged power in, downloaded marlin firmware, install repetierHost software in ubuntu 12.04 and it works. no issues seen so far. I don't know if I can post it all, but below are my build notes if it helps someone else: ============= my build notes for ramps 1.4 kit on 24v Intsall arduino ide for ubuntu 12.04, used the repository. sudo apt-get install arduino installs version 1.0.1 Marlin download to Taurino got marlin firmware from reprapdiscount US resalerlocation set arduino ide for Mega 2560 verified Marlin.ino project compile, no errors reported. connected usb to taurino, only usb. downloaded Marlin.ino project to taurino. complaint about no usb, arduino suggested another port which did work. removed usb to taurino. connected lcd header/ribbon cable to taurino. connected usb to taurino lcd and firmware worked.