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My wi fi goes out. I have fixed it 5 times by heating till it overheats & then placing in a fridge. Reboot and its back. Is there a permanent fix for this?

Hello, the only way to repair permanently is the reballing of ic wifi

Smartphonefix is correct, the WiFi IC must be reflowed. If comfortable attempting this repair there is a guide here: How to Fix iPhone 4S Wi-Fi Grayed Out

https://www.youtube.com/watch?v=miCgGhdM