Here's Why Your iPhone Randomly Vibrates & How to Fix It iPhone vibrates when charging with volume button pressed Massaging Heating Pad for Neck and Shoulder Back Pain Relief, 3 Heating Levels & 3 Massage Modes Bed Bath & Beyond 39614590 How to Put iPhone on Vibrate or Silent Mode The Evolution of iPhone Vibration Technology, Before the Taptic Engine revolutionized tactile feedback, iPhones relied on older vibration technologies. Initially, Apple used an Eccentric Rotating Mass Your phone doesn't vibrate by chance there's smart engineering behind every buzz., Inside, a tiny motor spins an off center weight called an eccentric rotating mass (ERM). As it spins, the imbalance