Error establishing a database connection-Redux

I am suffering the same old error: Error establishing a database connection. I have checked and rechecked my config file, changed my MySQL password. I have done everything that I could find to resolve the issue. I have installed literally dozens of WordPress sites over the years and this one is giving me fits. All I can think of is that I’m missing something that Hasn’t been discussed somewhere that I have read. This install is a local install on Ubuntu Server running LAMP.