User profile Synchronization Service stuck on starting in Sharepoint 2013 Farm

I am having 2 FE & 2 App Servers and trying to start UPS synchronization service but service is stuck and no update since last one week.

 I have done below but no luck .. Please support and advise..

- farm account is the member of admin group on server

- farm account is the member of WPG admin group.

- farm account admin right on the server.

  -FIM services are running with farm account.

Regards,

Mohammad Javed