Check your S4 after being shipped via ground service or any other rough handling. We have noticed that the main processor can come loose on some older models.
We have applied a thin layer of Goop to some in an effort to keep it from happening again.
Take the end screws out and lift the top cover off.
Look down on the main CB and find the square Siemens processor. Press it firmly back into place while holding the edge of the main cb.
Make sure the ribbon edge connectors are securely pressed down too.
Test with lid off.