I googled it and find https://forums.oneplus.net/threads/v...g.76462/page-2 that someone else is having the same problem with franco. I am so frustrated as it seems that only full reflash can fix the problem.
Anyone has others solution on it?
ROM: Stock CM 11S
Kernel: franco.Kernel v9
I did change according to http://forum.xda-developers.com/show...&postcount=271 today. Not sure if it relates to the issue.
PS Don't have the permission to ask in franco thread so I better post it here...
My solution is to accidentally drop the phone on the ground and make a scratch on the silver edge. And the vibration is back. It is a hardware problem. But maybe it is triggered by a software issue...