#!/bin/python3

import math
import os
import random
import re
import sys

# Complete the solve function below.
def solve(board):
    f=0
    for i in range(n-1):
        if ((int(board[i],2) ^ int(board[i+1],2))==0):
            f=1
            break
    if f==0:
        return "Yes"
    else:
        return "No"

if __name__ == '__main__':
    fptr = open(os.environ['OUTPUT_PATH'], 'w')

    t = int(input().strip())

    for t_itr in range(t):
        n = int(input().strip())

        board = []

        for _ in range(n):
            board.append("".join(input().rstrip().split()))

        result = solve(board)

        fptr.write(result + '\n')

    fptr.close()