rsReportServerDatabaseUnavailable

Hi guys, 

The entire SSRS is inaccessible. If I check the SSRS conf manager I can see that the problem held in the accessibility of the database Report Server but the DB is up and accessible via SSMS. Moreover the service browser is up and running in both machines (SSRS and the DB). I can ping all the machines. No idea what I can check more.

The error:

• The report server cannot open a connection to the report server database. A connection to the database is required for all requests and processing. (rsReportServerDatabaseUnavailable

Any suggestion?

Thanks