Photoshop Help
 

So im trying to use the burn tool, and i have the exposure on 100%, but nothing happens! the same thing happens with dodge, sponge, sharpen, and blur. everything else works.

Stupid question: Are you on the right layer? Also, for the burn/dodge, make sure you have the shadow/midtone/highlight setting set so it will do something noticable. Also make sure that the brush you are using has good size and coverage so you can actually tell the difference.

make sure the layer is raterized (if possible.) Thats usual only needed if you want to burn/dodge a pattern

Its prob the rasterization of the layer as stated previously.