Ok. You will need to do some investigating then so unplug the unit.
You will need to remove the top panel of the washer by locating the 2 screws on the back side of the panel that hold it on. Once the screws are out you will need to push the top panel back and then lift it off. Use the picture below as a reference for the next part:
Number A450 is the main pcb(power control board). It has a plastic cover on the front of it(A455). Make sure your hands are clear of the inside and plug the unit back in. Have someone turn the lights off in the room for a minute. Look at the board and see if there is a light(usually green) anywhere on that board. If the light is on, the display board(the one with the screen and lights) will need to be replaced. If there is no light, the main pcb will need to be replaced. In most cases it is the display board but, since the light doesn't come one, you may be looking at the main control board.
The part number for the main pcb is 6871ER1078T. It can be purchased at http://www.searspartsdirect.com/ or http://www.partselect.com/
If the light on the board is on then you will need to unplug the unit and order the display board. It is number F110 in the pic. To get to it you will need to remove the detergent drawer by pulling it all the way out to it stopping point. Around the back of the soap dish you will see a marked place for your finger. Push down on that spot and pull the drawer out. This will reveal the screw(s) in that area. Remove the screw(s). On the opposite side of the control panel(the right side) there will be 1 screw holding the control from the back side of the panel. remove that screw and the control panel should then snap off. This will give you access to the display board. You will need to transfer the knob and knob skirt to the new board. The knob will just pull off. The knob skirt has a little clip on it that you will need to work with to get it off.
The part number for the display board is 6871ER2078A.
Just to reassure you: This is a common problem on these units and I am very familiar with it. If you have any questions OR you hit any snags, just let me know. I have either seen it or heard about it so I will be able to help you out. I hope all of this information helps you get up and running as soon as possible.