Anyone know if it's possible to have the Arduino Pro Mini powered by 5 volts from an FTDI cable and a raw input power from a 9 volt battery at the same time? I know the Uno can handle this, but I don't know if the Pro Mini is capable of this. Seems like when I did try this, :
I might have damaged the capacitor. My Pro Mini no longer accepts power from the raw/vin pin. Everything else is fine on the board and in working order.
It depends. Weird enough the official Pro Mini does not show a diode so that means it's not possible. But on the image on that page and all the clone Pro Mini's I have here there IS a diode in line with the Vcc on the FTDI side. So they have no problem to have the FTDI cable connected when the Pro Mini is powered via Vcc or RAW. So look for a diode (or post a picture).
Are you sure you did not overload the regulator? When using the RAW pin you cannot really draw current from the Vcc pin. A few LEDs max.
But if the Pro Mini works on the FTDI (and does it work when you connect 5V @ Vcc?) but not when you use RAW the regulator is probably broken. Had this once. I removed the regulator and soldered a 78L05 across (on top) the header between RAW, GND and VCC (it's even in the right order 
).
Haven't been able to really dig into it and look at it. Need a better magnifying glass. But if most of the clones have diodes in line with FTDI then I would assume I overloaded the regulator. I was playing around with an RGB LED Strip when it happened. Using some Mosfets. Just one strip about 9 RGBs.