I have an HP Elitebook 840 G6. Yesterday it became unresponsive for no apparent reason. I think it may have completely discharged, but no trauma or anything. So now when it is not plugged in, when I press the power button it lights up and the charge indicator light blinks orange for a few seconds, then transitions to alternating orange and white for a few seconds, then turns off along with the power light. When it is plugged in, absolutely nothing happens. I tried unplugging the battery, hard resetting, but no change. Could you help?