I have just assembled 3D Nano. It powered up as expected, and everything looked good. I selected Autohome and head proceeded to travel to Z Endstop however it did not stop and I had to power off the printer (which I did promptly).
When I tried to power up a second time it does not work. I see pulsing red LED on main board, the INFO screen dimly pulses and the fan pulses slightly. When I disconnect the leads to the motors, the heater, thermistor, and end stops, it behaves the same only the pulses are longer and the the LED slightly brighter.
Without the power supply attached, I have connected to USB port and the main board seems to function okay: I see the full info display and I can select menu items and use read SD card. The thermistor appears to function and reports an increase in temperature when I press my finger near it. The repetier software also connects to the printer. I do not want to attempt and movement of motors or heating the element using only the USB port for power. The LED strip at top of printer (illuminating the VORTEX wording does not light up.)
The only other forum post I can see relating to this type of problem (below) seems to have been resolved using an alternative power supply; unfortunately I do not have a compatible one available to use even for troubleshooting. Does anyone have any suggestions? I think the board etc is ok and the problem is the power supply but how can I confirm and can I request a replacement?