also like CSL indicates there is another trick, if you unplug the connectors at the door and selector, you leave the connector on that goes to the port from door board and selector board, you can still communicate to each board individually without being connected to the CLC. this way you can be sure your door or selector card is communicating. with them unplugged, you can then try port in cop, and see if you establish comm to clc. same idea as CSL but while you are on cartop, you can at least verify comm to each board. selector ok light should be blinking, not on solid. if it is on solid, selector board probably no good if it was a power spike, always possible that it took out all 3 boards.