Menu doesnt work?

hi,
nav-menus.php is not working…
(wp-admin/nav-menus.php)
when i click “menus”

it is giving this error:
“503 Service Unavailable
The server is temporarily busy, try again later!”

yes, maybe it is a server problem but, how can i fix it without contacting server admin.

for example, using phpmyadmin how can i fix that problem? ( droping, deleting tables connected with menu. or somethin else? )

thnx