Search for what you are looking for like you are looking to buy/bid. When you get there, look directly to the left of the first item listing for the vertical strip menu titled "Categories" (not the "Categories" pull down menu at the top of the page) and follow that side strip down to "Show Only". The third checkbox under the "Show Only" heading is "Completed listings".
Check that box and the ended auctions will load, both sold and unsold.
I don't think you even need to be signed in.