hello i am new here. some help is much appreciated. i cut the 15 pin computer cable and notice there was three course and the rest finer wire altogether not 15 wire, and resolder all of them color matching. i had to cut the end off to pass the cable through a tube under concrete floor the head too big. after I resolder all wire and tried it, i get no signal via computer to enternal monitor. help any suggestion. pls.