How do you turn the portal of power for skylanders on?

My kids' Portal of Power stopped powering ON. I did the checks described in the manual... check batterries, re-sync, make sure it's close to the Wii Control box, etc., but no good. I opened it up to look inside and found that the (+) terminal of one of the batteries was not making contact with the receptacle in the battery holder. Most battery holders have a little leaf-spring there, but this one doesn't. I added a little metal shim at each of the three (+) terminal positions and it starts right up now. Not a very robust design in my opinion.

Good luck!