Dolphin Nautilus CC Acting Weird

by MJ

Bought new in 2020. At first it was doing the 10 second self test fail. Checked everything externally 10x over. Opened her up (Thanks LeisureLuke!) and the impeller motor was full of carbon dust. Cleaned all that, checked bearings, which seem fine. Motor box was dry with no sign of intrusion. Nothing else problem-wise is apparent.
Now, slight improvement - It comes on and goes forwards and backwards about 2-3 feet kinda shuffling to either side as it goes, with some wheelies here and there, thus only covering about a 5x5 foot area, and with no suction, although you can hear the impeller coming on. The motion of the wheels and brush appears strong. I was hoping I somehow put the impeller back on upside down, but no. Double checked the motor plug (into the circuit board) to make sure it wasn't reinserted backwards.