Chosen Solution

If my phone’s motherboard doesn’t have one of the small silver screws does it matter?

@jazonduh if it continues to work as it should and continues to be held in place by the other screws and for as long as nothing else is being held down by out, you should be okay without it. Of course the right thing to do would be to replace it. Get a complete screw set if you cannot determine the size of it from places like this You can also take one of the other screws to an electronics hardware store and see if they can match you up. It will be a metric thread.