I can only get a capital P with caps lock on, mid-2014 Macbook Pro
My first suggestion would be to reset both your SMC and NVRAM. 

[Reset NVRAM]


Shut down your machine. Yes, a full shut down, not just logging out.
Press the power button and then press the commandoptionpr keys. You have to make sure you press these keys before the gray screen appears or it won’t work.
Hold those keys down until your Mac reboots again and you here the startup chime.
Let go of the keys and let your Mac reboot normally.


Note: When you log back in you may need to readjust some of your system preferences (e.g. speaker volume, screen resolution, startup disk selection, time zone information, etc).

[Reset SMC]

To reset the SMC on a Mid-2014 MBP follow these steps:


Shut down your computer


Keep the MagSafe adapter (power cable) plugged in.
Press at the same time shiftoptioncontrol (on the left side of the keyboard) and the power button
Let go
Turn your computer back on with the power button.