It was suggested that I start a new thread. I was reading other like threads about water vacuums that shut off for no apparent reason. My subject machine shuts off after 7 seconds. I read about others that shut off after 2.5 minutes, others 10 min, etc. The problem is not the power supply because when I did the upside-down test it worked just fine. It's when I put the machine in the water and then turn it on. Again, after 7 seconds the power supply loses power. I have contact Maytronics and still awaiting reply but after reading some threads I guess they may not want to respond. This seems like it should be an easy fix. Does anyone have suggestions. Thanks. BTW this is my first post.