This is a variation on a theme, but no solutions offered in the other threads I've read have solved the problem.

I have loaded RedHat 7.3 on an AMD XP1500+ system. I let RedHat do the partitioning.

At level 3, I cannot log in using any account, including root. I enter the user name and password and am asked again for the login:

At level 5, I can log into KDE as root, but nothing else. I get the "Login failed" message. I've tried dropping and adding users and even creating new users, but the behavior does not change.

Ideas anyone?

Log in into single user mode ('linux single' at boot) and try to change root password using
passwd
Have you tries it before?

it's not going to be a password problem if he can login to root from 5 but not from 3.

that is strange. i've never heard that particular problem before.

...off to search the web

what does /etc/securetty say? Issue su - in the Xterm/konsole/Eterm (whichever you like the most), enter password for root and
cat /etc/securetty

I did try the linux single approach mentioned in another thread. I was able to change the root password and one of the user passwords. The changes were accepted. The result was the same. I could login at level 5 with the new root password, but not with the new user password. Level 3 continues to not accept any user/password combination, including root.

When I entered the cat /etc/securetty command, the following was returned:

vc/1
vc/2
vc/3
vc/4
vc/5
vc/6
vc/7
vc/8
vc/9
vc/10
vc/11
tty1
tty2
tty3
tty4
tty5
tty6
tty7
tty8
tty9
tty10
tty11

Thank you for your interest in this problem. All suggestions are welcome.

Some progress to report. When installing red hat, I elected to enable LDAP. But red hat did not start the ldap server when it booted. By using serviceconf, I was able to start the ldap server.

All logins now work for level 5. No logins; however, work for level 3.

Then you need to modify what starts in runlevel 3 - enable LDAP in runlevel 3 as well