A couple of weeks ago the display on my RB1 navigation radio stopped working. No display, radio would not tune to another station, only thing that worked was volume control. I had this unit repaired under warranty several years ago and it is not known for its reliability so I ordered a kenwood unit from Crutchfield. However, this morning after having some battery issues I had unhooked the ground cable from the battery, after hooking it back up and taking off for work I noticed that the display was up and running, good as new. Nav worked also. So it looks like I will have a new Kenwood unit for sale. The old "unhook your battery for 5 minute" reset looks like it works for more than just a ECU reset.