lmf96z71

ok...so ive had my 96 suburban lt for about a month now...and the 4x4 worked liek a week ago when i used it last...so i go to use it today and push the 4x4 button and it just blinks at me...when i hit the 4x4lo the transfer case shifted but the hubs still did not engage...i would just like to know what to check for and if something is bad how much it would cost....this is not a big deal and i can spend some money on it seeing as it only cost me $1600 in the first place...so any input is appreciated...thanks!