I’m having the same issue with my Dolphin Active 30i (aka S300 and same guts as S200). It ran great for the first year, then stopped climbing the walls, then would quit moving before the end of its cycle, and the run-time got progressively shorter, eventually only going a couple feet...power stayed on, controller on but unresponsive.
Marina got a replacement motor for me and that worked for a few months but then the same exact thing started happening. I re-seated the motor multiple times, fan spun freely, self-test was smooth, everything worked fine except the track on the gear side would want to skip a tooth every once or twice around. After a closer look, I noticed that the intermediate gear that connects to the drive brush gear was worn down more on one side (the side closest to the brush gear). The brush gear was only slightly worn, the motor gear and the other intermediate gear were fine. Problem solved...gear wears down, wheel wobbles, track gets off balance, motor gets overworked. Not quite:/
I replaced the gear, ran a smooth self-test, put the track back on... slightly better but still skipping. Took the track back off, re-seat motor, re-test...runs smooth and keeps going. I read in a post that the shape of the drive brush can start to get misshapen (slightly oval), so I took a look at mine and the brush and the connection hub still seemed perfectly round, but I did notice that the axle itself (hexagonal extension from the brush hub that the gear attaches to) was a little wonky...when it rotated it did not stay centered. It was very noticeable when I put the brush and wheels back on and ran another self-test... as the brush turned, the axle rotation was clearly not balanced. That’s gotta be it...axle rotates off-balance, causing friction between the gears, gear wears down, wheel wobbles, track gets off balance, motor gets overworked. Not so fast
I replaced the drive brush and all its components (including gear and axle hub), the passive brush and all its components, all four wheels, and both tracks. Did the self-test with wheels but no track and everything was smooth except for a very similar off-centered rotation of the drive brush axle (uh oh) and wheel wobble. I reseated the motor one more time for good measure...no improvement. I put the tracks back on, and although it was slightly better, the dreaded skip was still there. I’ve had it back in the water now for a few weeks...it made it up the walls for couple days, and ran full cycles for about two weeks, but it’s back to no walls and quitting a few minutes into the cycle. When I run the self-test with the track on it also quits a few minutes after it gets into the regular cycle. When I run the self-test without the track, the motor continues to run and wheel/gears turn without quitting even well into the regular cycle.
Is anyone else seeing this particular problem with the drive brush axle? Is it possible that the new one I just got is just a dud, or is this a manufacturer defect in all of them? Or is there a separate issue that I’m missing?
Video: Running with Track
Video: Running Without Track
