Help. Hi I have had my irobot roomba model 4000 now for 3 months now, I just LOVE it sooo much. I

Question

Hi I have had my irobot roomba model 4000 now for 3 months now, I just LOVE it sooo much. I have used it everyday since I got it. But now it is not working. I cleaned it all out I even sprayed it with that air spray can. What happens is, It starts to go then it acts like there is something in the way and stops then goes the other way, then goes off. What is wrong? Please help!!!