My son upgraded system and needs to have the terms and agreement accepted on the master account. I do not see master account/sub account management on menu pick anymore in order to accept T&Cs. What can I do to get into the master account and see the sub account again?
You should have at least two PS3 Users, each with a PSN Account setup on the PS3. One user would be his, and have his PSN Account. The other user would be yours master account with your PSN Account that created his PSN Account.
The way it should work is you login to the PS3 with your user, and accept the new terms, then he'd be allowed to login.
There have been issues with it in the past, so I don't know what'll happen with you.
Also, it would stand to reason that if you login to the website here, with your Master PSN Account (that created his Sub PSN Account) that you'd be able to accept the terms on the website, and he'd be allowed to login. But I'm not sure if the terms need to be accepted on the PS3 itself for a sub account to work.