Just picked up a VX today. Plugged guitar into the VX and the VX into my iPad 4. Opened Mobile Pod. The app knew that the VX was connected, but there was no signal into the iPad. The tuning app showed nothing. I tried headphones in both the VX and the iPad. I made sure the VX was set for guitar input. I also checked the instrument cable. I did not have power going to the VX. Any pointers?