Everything works except the camera keeeps "thinking" nothing showing up on iphone screen

That sounds like nature's way of suggesting it's time to upgrade your equipment to something more modern.
Drones have come a very long way since the P2

Hello there Bellenie.  I am sorry to know that you are having issues with your DJI Phantom 2 Vision and thank you for reaching out. The best way to help you with this issue is for you to send an email at support@dji.com . Thank you.

Two big problems with the P2V series these days

1)  Finding a mobile device that's compatible [solution:  get yourself a good tablet that's also about five years old or more]

2)  Finding a P2V series drone with a NAND chip that works correctly [solution:  flash the NAND]

It'll still fly fine with no FPV and/or no wifi provided nothing else is wrong with it.    Video will likely record fine.  Learn the lamp codes.  

Good luck

I have exact problem with my Vision 2.  It use to work.  Pulled it out of storage, and now it doesn't, even with original iphone.

Yes - storage will kill the FPV capability for the P2 and P3 series.  The P4 is different and can survive storage.  

You can flash the NAND yourself which will likely fix it.  https://phantompilots.com/thread ... tion-to-fix.145917/

Or OKSTUV on eBay will do it for you.  https://www.ebay.com/itm/Repair- ... :g:yJUAAOSw9y1fe-jP

Try to start it up at least once per month to keep it working.

Good luck.