GarminDevice.xml from another unit wont help you as the unit re-creates it from scratch at each boot cycle. Create a folder named Garmin in root, boot it and then check for the xml file. Other 1xxx devices [1100/1200/1300/1400] all will boot empty and create the Garmin folder themselves but 1690 might require it be created manually as do some other device series. Some 2xxx units are known to also need to have some other folders and files onboard, but try just creating the Garmin folder first.