Should you need to uncheck the Resources checkbox on page load, you can try to use OnAfterRenderView client-side event of WebScheduler and invoke HideResources(parameter) method to get the Resources checkbox unchecked.

function WebScheduler1_OnAfterRenderView(controlId, viewMode) {
    var WebScheduler1 = ISGetObject(controlId);
    var resources = WebScheduler1.Resources;

    for (var i = 0; i < resources.length; i++) {
        var resource = resources[i];

        WebScheduler1.HideResources(resource);
    }

    return true;
}

I enclosed one simple sample that shows how to have the entire Resources checkbox of WebScheduler unchecked on page load as attachment. Please have the attached file tested on your end and let us know if you have different scenario.