The most common problem reported by iPhone 6s and 6s Plus users was that of random shutdowns. The phone would automatically shut down because of a faulty battery. Apple announced that the devices which experienced the problem included a battery component which had been exposed to controlled ambient air for longer than the ideal span of time. This caused the problem and while replacements were being done, Apple also released iOS 10.2.1 to fix the issue.

Solution 1: Update your phone’s software

Check if your phone is using the latest software or not, since Apple released an update to fix the random shutdowns.

• Go to Settings
• Tap on General
• Look for Software Updates

If there are any updates available then download and install the update.

Solution 2: Take to Apple Care for Replacement

This problem occurred in iPhone in a limited range of serial numbers. Users could check their device’s serial number on Apple’s website and the affected devices can get a free replacement.