The device status LED can be off for several reasons:

• The device is currently in sleep mode.
• For USB powered devices, the power supply or USB cable has failed.
• For battery powered devices, the battery is discharged.
• Firmware on the device has disabled the status LED.
• During software updates, the status LED could go off for up to a minute.
• The device hardware has failed.

The first step is to attempt to put the device in DFU mode (blinking yellow). Hold down the MODE (or SETUP) button and tap the RESET button. Continue to hold down the MODE button while the status LED blinks magenta (red and blue at the same time) until it blinks yellow, then release MODE.

If you are able to get into blinking magenta or blinking yellow mode the hardware is fine, it's just a firmware issue that can be corrected by using Device Restore.