I removed the dishwasher from under the counter (disconnecting water and electric), confirmed that the springs were fine, and saw that the string had worn down and snapped on one of the tension roller assemblies. I ordered new tension roller assemblies (there were two in the package). I removed the side panels and the base to install them. The entire project took me about six hours for dishwasher removal, diagnosis, repair, and re-installation. This also included replacing the drain hose, which I discovered was cracked when I removed the dishwasher to diagnose the door problem.