Sorry but he still encounters problems,aniway if he contact you with email you can tell him his password of super mechs?
The only way to do this, is to go through the lost password process. If he remembers his username, and have access to the email address that he used to register for the account, he should be able to reset his password easily.
edit: the name -]Deff is actually invalid, plus it's not found in the member list. Tell your friend to make sure that the name he entered is corrected.