my hum came from my engine bay (fuel pump i would believe) and there was no solenoid click. It was prepping to start but since it was thinking that the clutch was engaged, it would not start. check you clutch swithces to see if they are burned out (if stock) or that the bolt is actually in place. i seriously doubt that it is your fuel pump or your starter relay, but then again check your fuse box to see if the fuse has not blown