I had a problem with the vibrator not working after battery and front camera replacement. I then replaced the vibrator, which still did not work, but I also lost the volume buttons and the mute switch. I didn't think I damaged the flex cable, as I was very careful and don't recall doing anything that could have damaged the flex cable. I decided to have another look at the connectors for the front camera, digitizer, etc. Turns out that the volume control and vibrator cable got detached - I snapped it back on, and got everything working again. So suggestion - before replacing the flex cable, check the connector first. The connector is located in the same area as the connectors for digitizer, screen and front camera.