My camcorder won’t turn on, unless…

I’m having a lot of trouble with my Panasonic camcorder. It is completely unresponsive, unless I press the tape eject button and then it will turn on for a second and then turn back off. If I repeatedly press the eject button over and over keeping it from turning off, it will actually load into the menu systems and start to display a video feed. It will even zoom and focus, but the second I stop pressing the eject button it turns off again and becomes unresponsive. What can I do to fix this? I got the camera for free so I am ready and willing to do any invasive surgery to fix it lol.