iPhone 4, since back glass replacement; less vibration

[alkemyst]

Since my back glass was replaced by Apple...the vibration mode on my phone is not so noticeable. Anything I can look at myself?

 

[TheStu]

Pull the back off and see if maybe something is blocking the motor? Should be in the upper right corner when you pull the back off.

 

[Adramalech]

I would highly recommend taking it back to Apple versus messing around with it yourself if you are still under warranty. If you crack it open now, it might void your warranty. Go back and let them know what the issue is...might get replacement phone out of it.