my navigation system in my 2007 escalade would not work anymore i cleaned it several times,it would work for a while,but not long, new disc no difference, so i changed the dvd navation mechanism.got it from china http://www.aliexpress.com/wholesale...+mech&catId=0&initiative_id=SB_20141121094552 took about 2 hours remove and change mechanism check the numbers on your unit before ordering the make different ones.cost $180.00 and 2 weeks delivery