Update the password in SharePoint using Powershell Script

Cause: You try to update the existing password for the domain account which you changed recently in your domain but not updated in SharePoint. When trying to update it in SharePoint using central Admin but not able to update it.

Solution: Run the below powershell command it will update your existing password which you updated in domain:

"Set-SPManagedAccount -UseExistingPassword -Identity domain\atou817"

Here Domain\atou817 is the account which i tried to update the password. The below screen shot is for your more referance.