Hello! We have a Polaris 9300 pool cleaner that we purchased second hand, of course when we got it home we plugged it in and it would act like it was about to start, the jet would go on and then the lights blink back and forth between cycle 1 and 2. The guy is being decent about it but we were really hoping for an easy fix. We watched the basic troubleshooting about making sure it’s plugged in correctly and the propeller is free of debris. Any suggestions?