I recently had my iPhone 3GS replaced at the Genius Bar. On the new phone, I noticed that it would vibrate really loudly, as if something in the case was vibrating along with the vibration motor. Here's how I fixed it:
1. I unscrewed the two screws on the bottom of the phone.
2. I took a suction cup and lifted up the display to about a 30º angle.
3. I moved the display over so that I could see the vibration motor (with it still connected).
4. I took my Philips #000 screwdriver and unscrewed the screws that hold the vibration motor in.
5. I then put the screws back and tightened them pretty tight.
6. I tested the vibrate function, and indeed it was much quieter, like my original iPhone!
1. I unscrewed the two screws on the bottom of the phone.
2. I took a suction cup and lifted up the display to about a 30º angle.
3. I moved the display over so that I could see the vibration motor (with it still connected).
4. I took my Philips #000 screwdriver and unscrewed the screws that hold the vibration motor in.
5. I then put the screws back and tightened them pretty tight.
6. I tested the vibrate function, and indeed it was much quieter, like my original iPhone!
