Hello, I just picked up a clean 2006 STS4 a few days ago for a good price. I'm in love with it. It has 150k mi on it and needs a few things. Most prominently is the display is blank at all times after start up, however the audio can be heard. I have not spent much time diagnosing it. I have noticed if I pull the fuse for the circuit or unplug the unit and reconnect the circuit the unit will boot up and work fine until the ignition is cycled off and back on. I've searched for similar symptoms but none of the threads I have come across never came across a solution. I did basic checks. I'm currently leaning towards poor battery. I keep forgetting to bring my multi-meter home from work. Any help is appreciated. Unit works flawlessly and adjustment to settings can be made and even my iphone can be linked through blue tooth.