My Scientific Atlanta Explorer 2200 decoder was completely dead. I found the switching power supply faulty. The power supply board is located vertically on the side of the cabinet. I found U3 (ICE2A265 short on pin 7 VCC) and C19 (22uF, 50V with a very high ESR). I replaced those two parts and everythings is now OK. I found the ICE2A265 at Digi-Key.