Help!

Hey everyone! I bought the LR3 off one of my husband's friends and he didn't have any issues. I got it set up the morning it worked fine for several hours. All of a sudden, I got the flashing blue light. I took everything apart, cleaned the DFI sensors, and put it back together. I'm using white Target litter box liners, they are tucked in and nothing is in the way. I still had the flashing blue light. I hit the reset button and that's when I got the fast yellow light. So I took it apart again, pressed the pinch indicator in to clear the debris, and reassembled. Plugged it in, hit the power button, still getting the blue light. If I press reset, it goes to the yellow light. It alternates between the two when I hit reset. I've also unplugged the cord from the base to hard reset it. The litter is under the fill line, I'm using a brand recommend by the litter robot website, and everything has been taken apart/cleaned ten times now. Should I go ahead and buy a new sensor kit, or does anyone have suggestions?