Hello,
When power up my Ramps 1.4 (using Sprinter firmware), the arduino became very hot and starts shutting down. Currently Ramps don't turn on (the red led isn't lighting). However, when using the test code it turn on! (I get the leds lighting, but no any movement)
Some pics:
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have you checked for any shorts on your ramps board, and also have you tried it with out the drivers on it.

oh and where are you powering it at.?