Hi,
Here’s a link to the ifixit [guide|59913] guide.
At Step.5 in the procedure you’ll see the antenna connections. Hover the mouse over either of the smaller images to the right of the main image and click on either. This will let you see both ends of the antenna connection.
At Step.7 in the procedure it mentions the vibration motor. You could check that it is connected properly or perhaps it may need to be replaced.
Here’s a link to the ifixit [guide|56834] guide which may be of some help.
Replacements are available online. Just search for ''Asus ZenFone 2 vibration motor part'' to get results for suppliers of the part