If you have installed Azure AD Connect with Password Synchronization
- (which you should even if you are using ADFS – see this blog for reason why)
And you have forced a Full Password Synchronization (e.g. by using a script as described here )
How do you verify if the Password Synchronization is working?
Open the application log in event viewer
- Look for Event ID 656 “Password Change Request”
2. Look for Event ID 657 “Password Change Result: Success”
3. Finally, browse to https://portal.office.com and verify that you can login into Office 365 with the new password