My 12X does the same thing.I have two packs, one Eneloop and one JR.I think that this is caused by low temp. Once the voltage gets about 10.4 volts the screen will flash once
and then turn on. Any lower in the voltage and only the landing gear default in the up position will let the screen come on. Ehen the gear switch is in the down position the screen will juist flash, but the transmitter will not turn on. I think I will have to buy a new transmitter, and transfer the info tothe new one. I can not trust this one any farther than I can through it.