No, not all of the Dead Sea Scrolls are fakes. You are probably referring to the 16 fragments owned by the Museum of the Bible in D.C. Even if these had been real, they weren't very important; they had no new textual information because they were simply copied from older editions of (real) scrolls. In fact, one of the ways they were ID'd as fakes is that the forger copied over a footnote marker from the edition he used. These scrolls had no provenance (meaning no one knew where they came from) and were written on a very different material than the other, authentic scolls.