Want to troubleshoot my fire alarm system having trouble with my 5th floor smokes they keep giving an alarm when there is'nt one could it be my end of line resistor? What could it be? Need a starting point.

The EOL only provides a current flow to prove the circuit is working. Could be a tripped or defective/dirty detector. You can remove one detector at a time to see if one is tripping out to general alarm.. You will get a trouble alarm because a detector is missing.