This may be the repeated question but the workaround I found for this issue is not working in my case thats why I am posting the question.

I've following service:

appRoot.service('MyService', function($rootScope) {

    var Messenger = {

        Temp: ,

        TempId:,

        tempMethod: function(Id) {

            TempId = Id;

            $rootScope.$broadcast('FirstCtrlMethod');

        }

    };

    return Messenger ;

});

In second controller:

appRoot.controller('SecondCtrl', function ($scope, $location, MyResource, NotificationService, MyService) {

 $scope.invokeFirstCtrl= function() {

        var Id = '2';

        MyService.tempMethod(Id);

});

In first controller:

appRoot.controller('FirstCtrl', function ($scope, $compile, $filter, $modal, $sce, $location, NotificationService, MyService) {

$scope.$on('FirstCtrlMethod', function () {        

        alert('I am from frist controller');

    });

});

Problem: The line $rootScope.$broadcast('FirstCtrlMethod'); is executing as expected but it is not causing to fire event $scope.$on('FirstCtrlMethod', function () {.. in the first controller.
I've used the differenct services in many places in my app in the same way and they are workig fine, I am not understanding why it is not working here.