Are you running your primers alongside a sample you know gives you a positive result? To avoid issues such as these you want to have DNA stored of a bacteria you know gives you a result when you run it. This will ensure you'll always know if it was your sample prep. or not.
As for primers, there shouldn't be any reason the primers you suggested aren't working. Fd1 / Rd1 are great universal primers as suggested, you could consider running these or any other stock primers you may have stored.