I have an SH2 as well but only ever use it in modem mode with my own wireless equipment.
First check the sticker on its base is there and legible! If you then do a pinhole reset with Hub switched on throughout - hold the pin for 60 seconds and then release and wait 5-10 minutes. The SSID's and the 2 passwords will revert to those on the sticker.
Use the wifi passphrase and admin password will revert to those on the sticker - make sure you use the password to log into the Hub settings page - NOT the wifi one.
You could also try the "free" SH1/2/2ac upgrade/replacement scheme - see the link below - as they are trying to get everyone onto Hub3's.
If you get the - "Ooops - please call" message, then come back here for more assistance.