Latitude E7250 19.5v separate bat, great keyboard, small 12" format (1) I have same model Dell E7250 power issue. (2) I tested the power supply and center pin to inner barrel gives 18.5 volts. Outer Barrel to inner Barrel gives 19.6 volts. Out barrel to center pin gives no voltage. (3) I tested the power port on the laptop to the pins on the mainboard where the power port plugs in: (4) Pin 1 has continuity to Center pin on barrel of the Power Port. (5) Pins 2 & 3 have continuity to inside barrel of the power port. (6) Pins 4 & 5 have continuity to outside barrel of the power port. (7) So all 5 pin outs have continuity. (8) When I unplug power port from mainboard and test with power supply.  The blue light on the power supply barrel stays on. (8.1) I get 19.5V on pins 2 & 4, 2&5, 3 & 4, 3 & 5. (8.2) I get 18.5V on pins 1 & 2, 1 & 3.