What is the problem with iPhone 5 Vibrator?

Hello everyone,

The problem I am currently facing is that iPhone 5 vibrator does not work. I tested two different vibrators and none of them worked on iPhone. However, both of them worked completely fine using external power supply. It is worth mentioning that Power, Volume and Silence buttons are working fine. I already tried to change flex cable as well, so I assume the problem is not in it.

The funny thing that from time to time it was working. However, later on it just died on me.

I tried measuring the voltage coming to the pins of vibrator on flex cable and it is being shown as 30 mV. So I assume the problem is either with pins of the connector or the actual chip which is responsible for controlling voltage output to vibrator.

Also, phone itself is completely fine, no water damage or anything. I am attaching picture of the connector pins as some pins look a bit damaged to me, however, not completely sure, therefore, I am asking here.

Thank you for your help!