On my list of upgrades to my Prusa i3 I have dual extruders (which is being worked on currently), and auto bed leveling (next on the list).
I'm seeing something that hopefully isn't contradictory.
For dual extruders, I've changed motherboard type to 34 - which disables the fan control in lieu of power for a second hot end. The fan extender then controls dual fans via D4/D5, with 12v power coming from the 12v lead next to the X axis stepper driver.
To enable power to the servos section of the ramps, it appears that D12 and VCC need to be jumpered (PS-ON and VCC to the left of the reset button on the Ramps board).
My concern is that A: I'm feeding power to the fan extender via the 12v lead, and B: I'm "enabling power" to the servo's via jumpering D12.
Would I only need to do one of these to accomplish my goal of supplying power for fans and the bed leveling servo or am I OK with both of these?
Thanks in advance.