Answer to: iPhone 7 Plus Boot LoopIn my experience the most common cause of a bootloop an an iPhone 7 is the Audio IC chip… or rather the lack thereof. This chip will loose some of its solder joints similar to how the touch IC would on the iPhone 6 plus. Here are some images showing where it is and how to get to it. The only real way to fix it is to remove this chip, re-ball, and re-solder it back. This does come with some risk and should only be done by an experienced professional. Also, with some of the later updates of iOS, most iPhones will boot up showing only a black or white screen before showing an Apple logo. This alone doesn’t indicate any kind of issue with your phone.
Answer to: How to stop the annoying moisture detected at the USB charging port.The moisture sensor is fairly sensitive, so if you have been holding the phone while covering the charge port, it is often enough to trigger the sensor. If you are sure the phone is completely dry and you are still having the issue, the only real fix is to replace the charge port flex as it has the moisture sensor on it. If you really need an immediate way to charge it, you can charge it wirelessly until you get it fixed. Some people have had success powering off their phone, then plugging it in, then powering it back on. Once the moisture sensor is faulty, this trick will not always work though.
Answer to: iPhone stuck in an activation loopI am not sure if this will speak to your issue specifically, but the simplest solution is often the correct one, so here is what we have found. The most common issue is that the device is locked to Sprint. Even if you put in a sprint card, the phone will often revert back to the activation screen because Sprint has not activated the phone on their end. From my experience this is the case only when you leave a sim card in the phone once it is past the activation menu, if you don’t have a sim card in the phone, it should remain there without reverting back to the activation menu. If it still reverts back you may have a more serious issue.
Answer to: Pressure spot after screen replacement?For the iPhone 6 in particular, the pressure-spot will occur if the ribbon Cable is slightly longer than the section on the frame (See Image) allows for. This is an issue that can occur when using an aftermarket screen. If you purchased the screen recently, I would suggest asking for a replacement as this is a manufacturing defect. This issue happens when the size of aftermarket chips, frame, and even ribbon cables are not proportioned the same as OEM screens.