Why does my Samsung Galaxy S3 no longer vibrate (except for right after boot)? Recently I switched my Samsung Galaxy S3 (model number SPH-L710) from TouchWiz (Jellybean) to SlimKat (KitKat) 4.4.2 build 4.1 stable. As of right now, the phone's vibrate function does not work except for when first booting the phone. The vibrate function works for around 30 seconds to a minute (I test this by repeatedly changing the volume from the quietest to vibrate using the rocker). Eventually, the phone just stops vibrating when this occurs, and no other app can get the phone to vibrate as well. 

I double checked all my application settings, but I haven't installed any new apps aside from the ones I backed up using Titanium Backup, and the vibrate worked fine while it was on TouchWiz. Is this a SlimKat bug or do I just need to dig harder to find the app causing it? If so, what are some problem apps/services that can cause this?
In my case I had turned on power savings mode. Am not sure but I believe that in 4.4.2 power saving mode comes with "Disabling Haptic Feedback" turned on. This can be rectified by going to Settings->My Device and then clicking on Power Saving Mode. There uncheck the "Disabling Haptic Feedback" checkbox.