I installed an XTL5000 with a W4 control head in my truck a couple weeks ago and I can't seem to get it to work. The first time it powered up fine but said "key fail." I went back to turn it on a couple days later, not having messed with it at all, and it gave me an error code FL 01/90. Looking online, it seems like this may be because the control head isn't communicating with the brick. I checked and tightened all the connections and turned it on again. Now it powers on but the screen flickers XTL5000, then beeps and goes blank. The control head stays on but keeps flickering. The guy I bought it from said it may be because the head isn't getting enough power. I tried hooking up the power cable to a 13.8v 30A power supply but the radio won't even power up with that. Anybody know what's going on with it?