Diane, first of all, I own two EX21 saws and love them. I am not saying they are better than other saws, but, I did have to make adjustments on both saws. One is a 2011 model and the other is a 2013 model. The first thing I did on the 2013 model was remove the plastic shroud. On both saws I had to set the upper arm tension to my liking. I do not like it staying up on its own when changing blades; I have just learned to hold the blade holder with my finger while inserting a new blade. I purchased both saws from Ray @ Seyco and I called him before making any adjustments and he guided me through the procedures. I know for a fact, he will be glad to help you over the phone and will guide you through any adjustments. By the way, your blade holders should not need adjustments, unless you have purchased a used saw. Now, I have had to replace the blade holders, due to wear caused by the number of hours I saw. The threads on the thumb screw eventually wear. I also replace the set screws pretty regularly and I constantly check my blades to make sure they are square to the table. If the set screws are not in the same position on the top and bottom, you will find your blades bending. Hope this helps and not more confusing.
Tony,aka,Toneman