Cannot log in after boot:-(

[don fisher]

When I boot to level 2 I receive the login prompt. But if I attempt to 
login as a user or root the login prompt just returns. I booted into 
single user mode and tried to fix the /etc/passwd, /etc/group and 
/etc/gshadow. Executing pwconv and grpconv all appear to work. pwck and 
grpck also are successful.

In single user mode I can su to my dfisher account, then su to another 
user account that requires a passwd, and then su back to root that 
requires a passwd. All are successful.

But when I type ^g and receive the login prompt, none of my accounts are 
accessible.

That do I need to do to make the system login work?

Thanks,
Don