There are several possible causes of your laptop not charging. The most common are: (1) A loose power cable. Make sure that the power cable from the wall to the charger is completely inserted. (2) A bent or broken DC plug pin. Check inside of the DC plug and make sure that the pin is not damaged. (3) A problem with the charger. If the charger brick is cold to the the touch despite being plugged in, the charger may be faulty. You may find more information on the HP Split x2 troubleshooting page.