#include<bits/stdc++.h>
#define int long long
#define fr(i,j,k) for(register int i=j;i<=k;++i)
#define rf(i,j,k) for(register int i=j;i>=k;--i)
#define foredge(i,j) for(register int i=head[j];i;i=e[i].nxt)
#define randfind(l,r) (rand()%((r)-(l)+1)+(l))
#define pb push_back
#define Times printf("Time:%.3lf\n",clock()/CLOCKS_PER_SEC)
using namespace std;
inline int read(){
	int x=0;
	bool f=0;
	char c=getchar();
	while(!isdigit(c)) f|=(c=='-'),c=getchar();
	while(isdigit(c)) x=(x<<3)+(x<<1)+(c^48),c=getchar();
	return f?-x:x;
}
inline void write(int x){
    if(x<0){putchar('-');x=-x;}
    if(x>9)write(x/10);
    putchar(x%10+'0');
}
inline void writeln(int x){write(x); puts("");}
inline void writepl(int x){write(x); putchar(' ');}
//inline void init(){
//	int t=read();
//	while(t--) work();
//}
const int Maxn=1e2+10;
int a[Maxn],b[Maxn];
int n;
struct node{
    int val;
    int sum;
    bool operator < (const node &x) const {
        return val<x.val;
    }
}e[Maxn];
priority_queue<node> q;
struct node1{
    int val,sum;
    bool operator < (const node1 &x) const {
        return sum>x.sum;
    }
};
priority_queue<node1> q1;
inline bool check(int x){
    while(!q1.empty()) q1.pop();while(!q.empty()) q.pop();
    fr(i,1,n){
        if(i==x) continue;
        node1 tmp;
        tmp.sum=e[i].sum,tmp.val=e[i].val;
        q1.push(tmp);
    }
    int lst=a[x];
    fr(i,1,n-1){
        while(!q1.empty() && q1.top().sum<=lst) {
            node1 tmp;
            tmp=q1.top();q1.pop();
            node ttmp;
            ttmp.sum=tmp.sum,ttmp.val=tmp.val;
            q.push(ttmp);
        }
        if(q.empty() || q.top().sum>lst){
            return false;
        }
        lst=q.top().val;
        q.pop();
    }
    return true;
}
inline void work(){
    n=read();
    fr(i,1,n) a[i]=read(),b[i]=read();
    if(n==2){puts("Yes");return;}
    fr(i,1,n) e[i].val=a[i];
    int sum=0;
    fr(i,1,n) sum+=b[i];
    fr(i,1,n) e[i].sum=sum-b[i];
    fr(i,1,n) if(check(i)){
        puts("Yes");
        return;
    }
    puts("No");
    return;
}
inline void init(){
    int t=read();
    while(t--) work();
}
signed main(){
	// freopen("input.in","r",stdin);
	// freopen("output.out","w",stdout);
    init();
    // printf("\nTIME:%.3lf",(double)clock()/CLOCKS_PER_SEC);
	return 0;
}