```go
package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
)

func main() {
	in := bufio.NewReader(os.Stdin)
	var t int
	fmt.Fscan(in, &t)
	for _ = range t {
		var n int
		fmt.Fscan(in, &n)
		a := make([]int, n+1)
		for i := 1; i <= n; i++ {
			fmt.Fscan(in, &a[i])
		}
		gangMap := make(map[int][]int)
		for i := 1; i <= n; i++ {
			gangMap[a[i]] = append(gangMap[a[i]], i)
		}
		gangs := make([]int, 0, len(gangMap))
		for k := range gangMap {
			gangs = append(gangs, k)
		}
		sort.Ints(gangs)
		if len(gangs) < 2 {
			fmt.Println("NO")
			continue
		}
		special := gangs[0]
		list1 := gangMap[special]
		c := list1[0]
		otherGang := gangs[1]
		listOther := gangMap[otherGang]
		b := listOther[0]
		var edges [][2]int
		for j := 1; j < len(list1); j++ {
			d := list1[j]
			edges = append(edges, [2]int{d, b})
		}
		for gi := 1; gi < len(gangs); gi++ {
			g := gangs[gi]
			lst := gangMap[g]
			for _, d := range lst {
				edges = append(edges, [2]int{d, c})
			}
		}
		fmt.Println("YES")
		for _, e := range edges {
			fmt.Printf("%d %d\n", e[0], e[1])
		}
	}
}
```