Reset F5 back to Factory assistance needed

If you don't have the root password, you may be able to boot the device into single-user mode and change the root password. From there you should be able to at least log in to the shell and manually edit the auth portion of the config. Check K14662 for the process on booting into single-user mode.

And on second read I noticed your comment about not having a console cable. K587 indicates the cable is a standard null-modem pinout (I'm assuming your system has a DE9 connector). I don't believe you can perform a factory reset from the LCD panel, but perhaps there's a hidden key sequence that I'm not aware of.