Why isn't my script changing the sprite's transparency?

Good evening, fellow developers,

basically I have a script for changing the transparency of an object but it is not working on a new object that I have attached it to (although it was working just fine for a previous object). The code is below

  #pragma strict
 var sprite : Renderer;
 var i : float;
 var rate : float;
 var trans : boolean;
 
 function Start () {
 i = 1;
 sprite = gameObject.GetComponent("Renderer");
 }
 
 function Awake () {
 i = 1;
 sprite = gameObject.GetComponent("Renderer");
 }
 
 function Update () 
 {
     if (trans == false)
     {
     sprite.material.color = new Color(1, 1, 1, i);
     i -= rate;
     if (i < 0)
     {
         trans = true;
     }
     }
     
     if (trans == true)
     {
     sprite.material.color = new Color(1, 1, 1, i);
     i += rate;
     if (i > 1)
     {
         trans = false;
     }
     }
 }

This is the modified code for my second object:

 #pragma strict
 var blackout : boolean;
 var sprite : Renderer;
 var i : float;
 var rate : float;
 
 function Start ()
 {
     i = 0;
     sprite = gameObject.GetComponent("Renderer");
 }
 
 function Update ()
 {
     if (blackout == true)
     {
         FullBlackOut();
     }
 }
 
 function StartBlackout()
 {
     blackout = true;
 }
 
 function FullBlackOut()
 {
     sprite.material.color = new Color(1, 1, 1, i);
     i += rate;
     if (i > 1)
     {
         blackout = false;
     }
 }

Before I forget, it is worth mentioning that my first script is to make an object appear to be blinking whereas in my second script the object is a black sprite that covers most of the screen and the alpha layer is preset to zero. Therefore in the second script I am trying to raise the alpha layer so that the screen becomes dark for the player. What am I doing wrong? I've tried googling my problem and have not found a solution that works (most solutions or just rearranged versions of the code I currently have but I tried them anyways) and looking at the script it looks right. Is there a setting in the Unity Editor that I have wrong?