Infinite Loop in void checkcard (memory game)

Class GameManager

 public Sprite[] cardface;
 public Sprite cardback;
 public GameObject[] cards;
 public Text matchText;

 private bool _init = false;
 private int  _matches = 5;

 private void Update(){
     if (!_init)
         initializeCards();

     if (Input.GetMouseButtonUp(0))
         CheckCards();
 }
 void initializeCards(){
     for(int id = 0; id < 2; id++){
         for(int i = 1; id <6; i++){

             bool test = false;
             int choice = 0;
             while(!test){
                 choice = Random.Range(0, cards.Length);
                 test = !(cards[choice].GetComponent<Card> ().inicializado);
             }
             cards[choice].GetComponent<Card>().cardValue = i;
             cards[choice].GetComponent<Card>().inicializado = true;
         }
     }


     foreach (GameObject c in cards)
         c.GetComponent<Card>().setupgraphics();

     if (!_init)
         _init = true;
 }
 public Sprite getCardBack(){
     return cardback;

 }
 public Sprite getCardFace(int i){
     return cardface [ i - 1 ];
 }




 void CheckCards() {
     List<int> c = new List<int>();

     for(int i = 0; i < cards.Length; i++){
         if (cards[i].GetComponent<Card>().state == 1)
             c.Add(i);

     }
     if (c.Count == 2)
         cardComparison(c);




 }

 void cardComparison(List<int> c){
     Card.Nao_fazer = true;

     int x = 0;

     if(cards[c[0]].GetComponent<Card>().cardValue == cards[c[1]].GetComponent<Card>().cardValue){
         x = 2;
         _matches--;
         matchText.text = "Combinações Restantes:" + _matches;
         if (_matches == 0)
             SceneManager.LoadScene("Menu");

     }
     for(int i  = 0; i < c.Count; i++){
         cards[c[i]].GetComponent<Card>().state = x;
         cards[c[i]].GetComponent<Card>().falseCheck();
     }


 }

Class Card

 public static bool Nao_fazer = false;

 [SerializeField]
 private int _state;
 [SerializeField]
 private int _cardValue;
 [SerializeField]
 private bool _inicializado = false;

 private Sprite _cardback;
 private Sprite _cardface;

 private GameObject _manager;

 private void Start()
 {
     _state = 1;
     _manager = GameObject.FindGameObjectWithTag("Manager");
 }
 public void setupgraphics()
 {
     _cardback = _manager.GetComponent<GameManager>().getCardBack();
     _cardface = _manager.GetComponent<GameManager>().getCardFace(_cardValue);

     flipCard();
 }

public void flipCard(){

     if (_state == 0)
         _state = 1;
     else if (_state == 1)
         _state = 0;


     if (_state == 0 && Nao_fazer)
         GetComponent<Image>().sprite = _cardback;
     else if(_state == 1 && !Nao_fazer)
         GetComponent<Image>().sprite = _cardface;
 }
 public int cardValue{
     get { return _cardValue; }
     set { _cardValue = value; }


 }

 public int state{
     get { return _state; }
     set { _state = value; }
 }
 public bool inicializado{
     get { return _inicializado; }
     set { _inicializado = value; }
 
 }
 public void falseCheck(){
     StartCoroutine(pause());

 }

 IEnumerator pause(){
     yield return new WaitForSeconds(1);
     if (_state == 0)
         GetComponent<Image>().sprite = _cardback;
     else if( _state == 1 )
         GetComponent<Image>().sprite = _cardface;
     Nao_fazer = false;
 }
   

}