SCOM Reporting Services-rslogon failed
After you change password for your service accounts for SCOM you can hit below issue if you have custom reports
There are few areas where passwords has to be updated in SCOM. beside the RunAs accounts you also have to update SQL reporting services credentials stored on your SQL server. Run the SQL reporting services configuration manager to update the credentials for RS (see below article to get more detailed steps)
If you still hit report error like below, highly like you have stored separate credentials credentials to accessing data sources. so I verified the new RunAsProfiles for SQL and make sure password is correct. Still I couldn’t get my reports. In this environment we also have lots of own custom reports which have do store own credentials for accessing databases.
so lets verify this 
Open https://SCOMRS/Reports and select the report which failed above with “rsLogonFailed” –> Data Sources –> Test Connection
Gotcha! this report is using separate credentials to access databases. if possible, you should avoid this and use the shared datasource option for your reports
as a key in SCOM, review the management guide for SQL to get better understanding around security. sometimes the permissions to monitor SQL instances have to be granular and restricted to the minimum to monitor health of an SQL server (a.e. highly secure networks like DMZ). I do highly recommend to checkout the SQL server management pack guide especially since the latest release there are new RunAs profiles which allow better and granular control
Microsoft System Center Management Pack for SQL Server
https://www.microsoft.com/en-US/download/details.aspx?id=10631
Below are some useful resources related to this topic
How to Change the Windows Service Account Password for the SQL Server Reporting Service
https://technet.microsoft.com/en-us/library/hh456426(v=sc.12).aspx
How to Change the Credentials for the Action Account
https://technet.microsoft.com/en-us/library/hh456432(v=sc.12).aspx
How to Change Credentials for the System Center Management Configuration service and System Center Data Access service
https://technet.microsoft.com/en-us/library/hh456438(v=sc.12).aspx
How to Change the Reporting Server Execution Account Password
https://technet.microsoft.com/en-us/library/hh456428(v=sc.12).aspx