[question] I have a RRD ramps + arduino + LCD shield.

[question] I have a RRD ramps + arduino + LCD shield. If i plug the usb cable i can see things in the LCD, if i unplug it just haves a dull backlight. I can see the arduino led on, so its on. If i move the encoder i can hear the buzzer. Any hint?, i wanna go computer less printing with that printer.

It doesnt matter if i connect 12v to the arduino or if it gets the power through the ramps.

anyone?, im having lots of troubles with the lcd shield, cannot use the sdcard neither.