Possible shorted/fried Laptop w/ Lipo

[hughman13]

I'll make sure to include as many details as possible.
I have an Arduino Uno for my University project, it is powered by two 18650s (however these were not connected when the issue occured). I have a L298N motor driver powered by a Lipo battery (30C, 11.1V, 800 maH), when I tested it, it worked perfectly and my motors responded to my GUI app on my Android.
I was working with my ME and the motors were not responding to my inputs. I was a bit put off because the Arduino was being powered from the Lipo (detached the 18650s and it was still powered) even though the only wire connecting motor driver & my Arduino was for grounding the motor driver to the Arduino. This wasn't occurring in my previous successful attempts. In order to assess the problem if possible it was the Bluetooth, I connected the Arduino to my laptop (Lenovo thinkpad X1 carbon) via USB and opened up my laptop to which it was not powered on, and would not turn on. I did also try charging the laptop with no success.
I haven't had this issue while powering the Arduino via 18650s or Lipo while my computer was connected to the Arduino.

I would like some input on how to
1) possible fix (I've heard of removing the battery & holding down the power button) as my warranty has worn off.
2) Why did this occur? How can I prevent this in the future? (CS major, not EE)
3) How to possibly get my files off the laptop as my code wasn't on github (the one time!)

My Arduino may also be fried (hence the lack of execution of input)

 

[hughman13]

Tried the solution of removing the battery & got it to work, for others who may see this post I'll describe the process.
1) Unplug the power adapter (charger) from the laptop
2) remove the battery (external or internal)
3) Hold the power button for a minimum of 30 seconds (this drains any left over power)
4) plug in power adapter
5) power on
6) After success, power down the laptop and insert your battery in.
Hope this helps!