Any data submission going to white screen; no redirect. Functions or Post issue?

Hello all,

Thank you for the help, in advance. So, like a responsible WordPress’er, I backed up files before I made any changes. I edited the wp-config, and functions file as per a tutorial on the web. When neither of the options worked, I deleted what I had entered and reverted back to the original file. Now, anytime that I update a page, activate a member, edit a post, or any other type of data submission, I get a white screen with nothing on it. It refers to the post.php in the web address area. The changed take, however there is no redirect back to any page. It dies on a white page with no errors. What the heck did I do? I have attempted to restore from a back-up, but no joy.