Unable to Configure a Repository in CMC

Hi Experts,

I have been working on this scenario. Please let me know if this work.

1. Server has two instances of SQL SERVER(Say InstanseA and InstanceB).
2. InstanceA is used for all the previous configurations of all Local Repositories.
3. Now, I have to created a database in InstanceB and defined it as Local Repository using Repository Manager.
4. Here comes the challenge, I try to configure the newly created repository in InstanceB in the Central Management Console.
5. I see error message "There is a problem to connect to repository: [Cannot open database "XXXXXXXX" requested by the login. The login failed. ClientConnectionId:7b69c087-d0b4-4803-9fab-d9439d4a4e66 ".

Expecting a quick fix for this. Thanks in Advance.

Santhosh