Total after if condition

Albawani 

Try it like this.

Debit Closing =
SUMX (
    VALUES ( Table[ACCOUNTID] ),
    IF ( BSBankTrans[Balance] > 0, BSBankTrans[Balance], 0 )
)

You will need to change the name of the table to match whatever is in your model.  It is the table that has the [AccountID] field.