Soft start 3V3_FMC
When the board is operated with an external power supply then V4 is switched on when all voltages are present 3V3 is enabled (EN_3V3). A sudden switch on draws a lot of current from N2 (EN29A0Q1; 12V->3V3 @ 10Amp) which has over-current protection that may trigger. Add a 330nF capacitor parallel to R333 and a resistor of 1K8 between the Gate-Source of T7. This slows down the transition from non-conducting to conducting state, and hence significantly reduces the FMC inrush current. In order to please the 3V3_PCI power supply, the same trick (470nF and 1K8) should also be applied to R139 and T3.
Modifications and measurements on SPEC7v2 in order to SoftStart_3V3_FMC.pdf