#include<bits/stdc++.h>
using namespace std;
char a[2000][2000];
struct Step{
int x,y,s;
}; const int dir[4][2]={{-1,0},{1,0},{0,-1},{0,1}};
bool vis[2000][2000];
int n;
queueq;
void solve(){
cin>>n;
for(int i=1;i<=n;i++){
for(int j=1;j<=n;j++){
cin>>a[i][j];
}
}
while(!q.empty())q.pop();
memset(vis, false, sizeof(vis));
q.push({1,1,0});vis[1][1]=true;
while(!q.empty()){
int x=q.front().x;
int y=q.front().y;
int s=q.front().s;q.pop();
if(x==n&&y==n){
cout<<"YES"<<"\n";
return ;
}
for(int k=0;k<4;k++){
int _x=x+dir[k][0];
int _y=y+dir[k][1];
if(_x>=1&&x<=n&&_y>=1&&_y<=n&&!vis[_x][_y]&&a[_x][_y]!='#'){
vis[_x][_y]=true;
q.push({_x,_y,s+1});
}
}
}
cout<<"NO"<<"\n";
} int main(){
int t;
cin>>t;
while(t--)solve();
return 0;
}