Mounting gimbal to a p2 v2 non vision

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I posted in the phantom 2 section but did not get much response. I have had my phantom since dec and have flown several times love it! Got a gopro hero 3+ black and purchased a h3-3d gimbal connected it to existing power cord on the 2 and connected to gimbal installed the interference board turned the p2 on and a puff of white lingering smoke came from the right side of the gimbal. The red light did illuminate on the side and I was able to tilt the gimbel using the silver roll knob on top of my controller. It would not stay where I left it it would return to the previous position once releasing the knob. It also did not have a very big range of movement. This is the second gimbal that has had the puff of white smoke. I can't return the p due to it being over 30 days but can return the gimbal. Is there an issue with my p2 is there a way to check voltage on that power cable will dji service my p2 and how long will it take does anyone know? Very flustered with this issue. Would think they would want to help.