If you manually installed it, are you sure you installed the correct ROM for the exact model of your phone? There are many different versions of the S3 (depending on the carrier and region), and if you install the wrong ROM, it can cause problems.
Its a galaxy s3 from sprint walmarts version of it threw straight talk is there any possible way to download a boot file in my sons phone as I do not have a pc atm
Sorry, but I don't think that'll work. I don't have any real experience with this kind of thing, though, so I'll have to defer to other members. Good luck!