Yes,
You see,
The camera pulls power from phantom mainboard, then the power passes through, the gimbal, and back to the wifi unit.
So that being said, if the gimbal boards fails, it most likely is not relaying the power to wifi module.
There is a bypass, you can perform, to test the wifi, but it is a son of a gun, unless you have a spare set of wires.
But if you are up to the challenge
On your wifi module, there are 3 plugs, 2 small plugs on the side, and a larger plug on the END. the larger plug on the end, is the plug we are after, it has a pin you must push to replease the plug ( it is easier to remove the Phillips screw holding the wifi down, then gently pry wifi module loose ( it is double sided taped down ) once loose you can unplug the wire from module, now track the wire down and out the belly of bird ( you'll need to remove the USB PORT PLUG, as I'd doubles as a wire tie down as well., you need to remove the wire in question completely.
Now we have wire, UNPLUG the wire going to the CAM PORT on phantom mainboard, then plug the wire we removed to the cam port, then back into wifi module, this will power the wifi temporarily, to see if you have transmission.
( NOTE: some mainboards have 5 port cam port, others have a 6 port ) make sure plug is in right spot if you have a 5 port plug, and 6 port mainboard!
Now turn on phantom and test for signal, you can also trace hidden wifi signal ( MAC address ) through android app ( InSSIDer app ). But you have to pay for it, around $10, or less.
Once satisfied it is working, then replace wire, the way it was, replace USB PORT, ect. It is a total pain in the rear, but at least you'll know, but
Im telling you, it is your gimbal board, 100 to 1!
J Dot
Hope this helps!