iPhone 6s Plus radio repair
My wife has an iPhone 6s Plus 64GB Rose Gold. It's been having issues with randomly dropping celluar service with the only workaround to restart the phone or toggle airplane mode. Sprint has sent of this phone to apple for repair.
My question is, what is the common repair for this issue? Do they replace the board? The entire phone? Also, I know that iPhone 6s Plus is pretty much end of sale at this point, so how does that affect how they might repair this phone?
*Status of the repair right now reflects that they haven't looked at it yet*
iPhone 6s Plus, iOS 10.3.3, SPRINT