Place turkey carcass, wings, and giblets in large pot and cover with 2 1/2 quarts water. Bring to boil and add carrots, onion, and celery.
Cover pot and reduce heat. Simmer for half-an-hour, then add salt and pepper to taste and chicken-soup mix. Continue simmering for 45 minutes.
Remove carcass and discard. Cut meat from bones in small pieces. Return meat to soup and discard bones.