I have Dewalt DW744 type 2 table saw. While using it last week I noticed a sharp decrease in power follow by sparks from the motor. I replaced the brushes hoping that would solve the problem but it did not, any suggestions?

If the brushes when while you were using the machine you may have also damaged the armature, what the brushes pushed againist. Most home owners are better off buying a new motor than attempting this repair.