Like many others, I started getting 4 beeps and a solid red light indicating a stuck roller brush. I went to this site for information and saw some suggestions to get it working and although the unit would sometimes work it never lasted long and didn’t seem to have anything to do with cleaning the roller. The remote to move around was still working and I noticed one of the side brushes had stopped spinning.I opened the unit up and to my surprise the insides were clean, almost no dust or pet hair was in there so I opened up the gear assembly as people here have mentioned broken gear teeth, this was not my case. It seemed like the motor was malfunctioning as it just didn’t turn even when removed from the gear box. I was going to try and find a replacement motor but decided to switch the side motors just to be sure it wasn’t the motherboard and low and behold, it turns out it is the motherboard. I have just used a multimeter and it appears as though the motor gets .1V when it is turned on but not idle, as soon as I use the remote the other spinner works fine as does the vacuum but the spinner on the faulty side of the motherboard gets 0V.
My unit is off warrantee but I’m posting this here so that others getting the 4 beeps and solid red light don’t assume it must be a stuck roller, turns out it can be an electrical issue on the motherboard. I just wish I could buy a replacement motherboard…