Hey guys,
I flew my drone a few weeks ago with no issues whatsoever. Yesterday I took it out and first the motors wouldn't start. I got a "compass stuck" error twice. Rebooted the RC and AC, got the compass error one more time, still couldn't take off. Shut down RC and AC. I took it home and booted up. Recalibrated compass. This time, no compass error but now, no video feed. Black screen. I got a "no image transmission" signal a couple times, but it disappears. Now, when I start up RC and AC and connect the app, I get no error messages but also no video feed.
I've relinked RC and AC, signed out of the app and signed back in, and am now uninstalling the app.
I am flying the Phantom 3 Standard and using an iPhone 7+. Firmware is up-to-date. I can control the gimbal no problem, I got the motor to start up last night and hovered the AC, but still no feed.

I've seen many different explanations online through tons of searching, but nothing solid. Is my wifi burned out? Do I need to downgrade firmware? Something else?

I did try to use a third-party battery when the issues started (I had no idea it was such a problem--safe to say I am returning that battery and will not ever purchase third-party again) but the issues continue to happen when I use the original DJI battery. Did I somehow cause irreperable damage to the system by plugging in a third-party battery ONCE? I'm out of warranty regardless, as this particular craft was purchased in June 2017.

I have a shoot in two days and am very, very eager to resolve the issue. All help appreciated. Thank you!

Hi, thanks for reaching DJI Forum. We do apologize for the troubles you had with your DJI Phantom Standard. Kindly check your latest firmware of your aircraft. Also I'd like to know if your mobile data is turned on. We suggest also to put the phone in airplane mode so as to not interfere the wifi signal. We're here to help you. Thank you.

Unplug the multi wired pin at top of gimbal., then plug it in again.  Sometimes this resets camera and gimbal.