mine doesnt rattle but you shouldnt have tampered with the screws mate, is there any scratches or anythin on them?
you should look for a tear-down vid on youtube to try n narrow down what could be rattling and see if its anything important.. could be the headphone socket if its had a knock and guarantee might not cover that
global s3, UK. Ask me anything and ill reply even if its just an intelligent (or stupid) guess