I recently noticed that my keyboard back-lights are not working. It lights up during boot up, but they the lights go out and do not come back on. Any suggestions?

I recently purchased the following laptop.ASUS G74SX-XT1 Intel Core i7-2630QM 2.0GHz 16GB DDR3. Also purchased a Seagate Momentus Mobile Hard Drive. Model # Seagate ST9750420AS,750GB, 2.5", 7200RPM, 16MB SATAI've installed the drive in the 2nd dirve...