The image would be clearer if you upload the picture as an attachment, rather than a picture of a picture. I agree there is no F3 marked on the drawing key. It will be a fuse, and the F1 and F2 marked are in the main switching feed on the black and white wires from the transformer, so should be easy to find.
People do this out of the goodness of their hearts, so it's good practice to put some effort into describing the problem, or at least say 'please' rather than post a five word demand with capitals as your first post. If you can't be bothered to tell us what's wrong and why you want to find F3, why should we be bothered to help you rather than you paying a local welding expert?