Why won't my cell phone vibrate when I get texts?

My LG Cosmos recently started to not vibrate when I get a text. It doesn’t happen every time, but more often than not I look down and see I have gotten a text without feeling it vibrate.

Yes, my settings are such that it should vibrate. I am positive. If you suggest that I will be very sad that you don’t read details in questions.

When the camera broke it was as easy as going inside and pushing on the lens. Is there an easy way to get it to always vibrate again? I’m assuming I just dropped it funny.