NBU Appliance Admin access via putty ssh is denied

I've been loggin in remotely to NBU appliance via putty ssh until I configured SRM (IPMI) and practically click Console Redirection button. After that I cannot log in anymore to appliance via putty (access denied), though login directly to appliance via KVM is fine.

How can I bring the access back? Any idea?

Appliance 5230, Media server role, ver 2.6.0.3.