Please try:
1. cPanel --> MySQL Databases
Current Databases
aaa_jo151 0.00 MB aaa_jo151 X Delete Database
Click on the user
Check ALL PRIVILEGES on the next screen Even if all the other boxes are checked, check "ALL"
Click "Save Changes"
Repeat for all db users
2. Make sure that the config, configuration, settings / ini, php file for your blog has the database host set to 'localhost'