About every second time I have loaded the FMC and prepare for take off I cannot engage A/TThe I start all over making exactly the same inputs and then i works.If I engage the A/T as the very first thing before opening the FMC the A/T stays on and I have no problems with it.I always start with everything running without caring about all the knobs and switches on the overhead panel.When I have a black panel I choose a Cessna and return to the B737 so I assume it has nothing to do with generators or the like, which I read in an answer to an almost similar question.Hans FogDenmark

Hans,Be sure to check your generators overhead...http://ops.precisionmanuals.com/wiki/PMDG_..._will_not_latchHope it helps,

When you say generator switch i guess you meen the gen 1 and gen 2 switches on each side of the APU GEN in the second column in the square that is headed by the GRD PWR OFFThere is no light in the GEN OFF BUSesI can make them light up by selecting offThe light goes out when I switch to ON - and the switches return to neutralHave I understood you correctly?Best regardsHans Fog

Hans,That is correct. No light is good. With ENG GEN ON you should be able to ARM the A/T with the switch on your MCP.Hope it helps,