7 year theory

I have a question.

I know that after 7 years things on your credit fall off, but does the 7 year time period start over with each new collection agency that the account is sold to?I have a debt with Discover originally that has been transferred for the 4th time to a new collection agency.

I understand the process of buying debts but on my end,do I have to being another 7 years with this new creditor?