I have a user account on my RHEL 4 server (yes 4, it's not a typo). His password expired so I changed it for him. Since I did that, he is no longer able to ssh to the server.

When I am on the server as root, I tried to run "su - useraccount". It immediately errors out with "incorrect password".

I verified that his account was not locked, I tried resetting the password again, and can see the last password change on the account is today. The shadow and passwd entry for this user are fine, and I don't see anything in pam.d/su file that would prevent this.

Does anybody know why I can't su to a user account from root?

Did the user's shell get changed? Check /etc/passwd and try changing it back with chsh command.
http://www.cyberciti.biz/faq/howto-c...d-login-shell/[COLOR="Silver"]

The shell didn't change. I did just issue a change just to see if it helped, but still get the same error.

I fixed it.

When I ran "faillog -u user", I saw the failure count was at 15. So I ran "faillog -r user" and that cleared the failure count. Once that was cleared, I was able to su to that user.