Hi,
Please do try these troubleshooting steps that may help in solving that issue.
- Start by doing a hard reboot, remove the battery and unplug the AC adapter then press and hold the power button for 20 seconds and test it once it boots back up to the desktop.
- If it doesn't work do connect an external USB keyboard and test weather the same problem will persist or not.
- If it works fine using an external keyboard , do uninstall/reinstall the keyboard driver.
- If all these will not work that means it's a hardware problem (the keyboard itself).