When you need to change the Config Manager admin password, you need to make that modification on several places.
1. Active Directory:
We first need to change the smsadmin password on Active Directory.
2. Database Server Services:
Log on to SQL server and open up services.msc. Then change service account passwords for these 3 services
SQL Server service, SQL server agent, SQL Server Reporting service
Restart those services.
3. Reporting Services Configuration Manager:
Log on to SQL server and start Reporting Services Configuration Manager > Click Service Account Tab and change the password > Click Database Tab and click Change Credentials and test the connectivity
4. Config Manager Console/Accounts:
Log Onto SCCM Site Server, Administration > Security > Accounts > Select "sccmadmin" account > right click Properties Change the password
5. Config Manager Console/Client Push Account (If you are using Client Push Method to install the Clients)
SCCM Console > Administration > Site Configuration > Sites > Right click on the site >Client Installation Poperties > Client Push Installation > Accounts > remove and then re-add smsadmin with the new password