I had this happen to me, but none of the above worked. What did work was using a hairdryer on it. (cool setting) I remembered I had been at a splash park a couple weeks prior and thought maybe some moisture had gotten in. My fix: I opened the side rubber flap and took off the PC flash cap. 5 minutes of blowing air (cool) around the switch and into the USB/HDMI ports did the trick. A week later it did start to act up again, but another few minutes of hairdryer took care of it. Me thinks that switch isn't as weatherproof as the rest of the camera.