Full Graphic Smart Controller powers off when USB cable unplugged

Hello,

I installed the RepRapDiscount Full Graphic Smart Controller, and it is working very well when the USB cable is plugged in. I can run prints, adjust settings, etc. However, when I disconnect the USB cable from my Ramps 1.4/Arduino Mega the display shuts down. How can I keep it powered on without the usb?

It sounds like your RAMPS is getting 5V from the USB cable and not the external power supply, and you never noticed until you after you installed the GLCD and first tried to unplug the USB cable.....

I agree with the above.

If your running 12v Check you have diode D1 installed (its under the X and Y pololu drivers) (middle rectangle in image)



This diode supplies the mega with power from the ramps.

NB If your running more than 12v.... you cant use D1, it will burn out the mega*.

*there are ways around this...

Edited 1 time(s). Last edit at 08/01/2014 10:18AM by Dust.

I have D1 installed and if I unplug the USB the arduino shuts down. Any idea on what to check next?

Is the D1 in the right direction?
Try to measure voltage from ramps, I've seen broken wires and also bad diode...

What sort of PSU are you using on your setup?

Is it an ATX PSU, and if so, how are you controlling it to switch it on/off?

I ended up pulling D1, which tested fine, and powering the arduino from the 5v vsb on the atx on the 5v VCC. I have the green wire on the atx going to the PS-ON pin and as of right now I can run the printer without the pc attached which is awesome but now I am trying to configure it so that the arduino can control the psu standby/soft off state so that I can shut down the printer and psu while arduino/LCD stays powered by the 5v VSB. That way I can start a print and leave it unintended and then have the arduino power down the psu on completion. Right now it is either everything powered on or everything powered off and I'd really like to make use of the M80 (psu power on) and M81 (psu powered off) commands.

I have a question for you Rav0506 . Since you wrote your comment on 9/24/14 have you ever: 1) had the 12v lines connected to your ramps board and have your computer plugged into the arduino usb connector at the same time you were connected with the 5vsb to the vcc pin and the ps-on pin on the ramps board with no ill affects to boards or computer with the computer connected and on and the atx power supply plugged into the wall? If so as a second question: 2) did you ever have the atx power supply powered up supplying the 12v with computer still pluged into the usb?