If your Maytronics moves forward, then back, then stops, read this post for why it happens...

by thehobe
(Northern California)

The Maytronics Dolphins work well...when they work. They have a fairly sophisticated internal controller the drives each of the 2-3 motors inside their units. The control board has the capability to measure the loading on each motor and decide if the motors are underloaded or overloaded. If the electronic module decides that the loading does not look correct or if the circuitry is broken or has drifted out of the expected allowed measurements, the control board will shut the motors down in as little as 10 seconds.

This is the common thread through most of the posts on this board...not working!

Even if the Dolphin breaks in the first day, Maytronics expects you to pay for the warranty return shipping!

Maytronics does not support owners doing their own repair. I'm sure their reasons involve lawyers and lawsuits. Even though the maximum supply voltage is about 37V and is transformer isolated, there is still a fair chance that an owner could hurt or electrocute themselves in the worst case.

There is much more detailed information in this board to look at.