More information on your particular saw ie. brand, size, mod. number would've been helpful. On most contractor grade miter saws there is a stop you can set that will only allow the blade to drop the set distance. It is located towards the spring. Try to drop the blade and look for the arm of the saw (what the blade is attached to) contacting a metal lever and flip it out of the way. Some lessor grade saws have a bolt that stops the arm
Mo from Colorado, December 2008