Obi200 software has been updated in 2016 and because of which your obi will no work, even though there will be dial tone but call will not go through. To update follow the following steps
On obi phone dial ***6, it will tell you that software is available, hang up for software update. Simply hang up.
Pick up your obi200 phone after some 15 min and it should now work!
To find IP of your obi, dial ***1. Then you can type that IP in browser and enter default password of admin/admin to login into Obi dashboard.