Now seeing your code, some things needs to be adjusted..
When accessing a server object from javascript, always use <%= ObjectName.ClientID%> because your parent control name can chnage and it will cause problems trying to find whats gone wrong.
Update your code to this simple line
function Call() {
$("#<%= Hidden_Link.ClientID%>").click();
alert('hi');
}
OR use this
$("#<%= Hidden_Link.ClientID%>").on("click", function() {
alert('hi');
});
$("#<%= Hidden_Link.ClientID%>").trigger("click");
REPORT IF YOU STILL HAVE ANY ISSUE ELSE MARK AS ANSWER