OK, I love this little machine the 3.0 size is much better then my last 1.6 Media MA50. And the cost is still reasonable. I did check the door latch for operation by operating the machine and pressing it. Looking at the machine from the back, its on the top right side just under the metal frame. Kind long a few inches semi clear white and easy to test, just used my finger and machine turned off. I describe testing the voltage with a pen electrical tester and inserted a piece of plastic to the pump wire connection to make sure I was getting a proper reading. The largest hose was the most annoying part because of the clamp being difficult to operate. Best way was to mount the pump, then connect hoses plus wiring. difficulties is about 6-7 out of 10 because of location and my stomach got in the way for me. Any questions just ask and hope you guys enjoy the video!