Megatronics v2.0 problem , neeed help please

hi every one,
My graduation project seminar is after 6 dayes, today morning, the main bord which is megatronics 2 get ruined.
the problem is : when I connect the 12 V power , no thing happens... no leds is on or any thing else , but if i connect the usb cable, every thing is good but the steppers wont move on the 5 V as you know.
I wonder if any one faced this problem before and what is the solution , or what u advice me to do?

CCT diagram shows two fuses and a voltage regulator.

I would start with those

f2 is under the board... f1 is on top between the connectors

Edited 1 time(s). Last edit at 05/30/2015 09:36AM by Dust.