Chosen Solution
I replaced the screen and after awhile the wifi button cannot be activated, should I replace the motherboard?
No, you will probably just have to replace the wifi antennas, which is probably what got ripped when you opened the device.
Sounds like you didnt reseat the wifi module properly, or as you were dismantling it you cracked part of the ribbon cable.Check , reseat, or replace the wifi module. I assume you tried doing the cold reset and switching in amd out of airplane mode, this is usually a fix for airplay too when that “greys” out.Hope this helps.
Replace your wifi antenna iPad 3 Wi-Fi Wi-Fi Antenna Replacement
