RSS feed errors

My RSS feed was showing as “obsolete feed’ in Feedburner. It said my feed had moved, but entering the address it showed as the new feed gave the same error. I deleted the feed but now I can’t get any valid feed.
I have tried http://example.com/?feed=rss
http://example.com/?feed=rss2
http://example.com/?feed=rdf
http://example.com/?feed=atom
http://example.com/feed/
http://example.com/feed/rss/
http://example.com/feed/rss2/
http://example.com/feed/rdf/
http://example.com/feed/atom/
Every one comes up “Received HTTP error: “Feed not found error: FeedBurner cannot locate this feed URI.” while fetching source feed.”
When I click on the check validity link it says there is a 404 not found error.
I have other WP sites with feeds that work.
Any help would be really appreciated.