inspiron 1545 keyboard backspace button not working

I have the dell inspiron 1545 and im currently running windows 7 and recently the backspace button just stopped working. How can I fix this? I tried to blow out any dirt with compressed air, and I even took off the key cap and made sure it was free of any dirt or debris underneath it. All of my clips are fine and the little rubber cup spring underneath are all fine. So what can I try now to fix it??? what wrong with it??? PLEASE HELP>>>>