Worked for awhile now... When I am setting up EFIS for basic flight the AT ARM switch will not stay in the arm position. Below the MCP is a three light panel with A/T P/RST blinking. I press it and it goes out. Reappears when I try to select AT ARM. I read the Auto Throttle Care and Feeding but it is much to confusing for me. Any help wp=ould be appreciated.

Hi I think you might need the flight director switch on first.Peter

Most of the time when this happens to folks it's because they've forgotten to turn on the engine generators after engine start.