Why are some keys not working?

Well the min reason for this are:

• Water or Liquid Damage
• Keyboard Ribbon Cable is Loose or Damaged
• Driver or Firmware Issue
• Internal Keyboard Circuit Damage

So Check you keyboard for all of the issue mention above, And also try to use a another keyboard and check does the issue exist, If yes the outdated or corrupted can be the main reason for this so updated your keyboard driver to it's latest version.

Hi @annikaarke96654

Has the keyboard gotten wet?

If it has gotten wet or even if it hasn't then it could be a faulty keyboard matrix, but in trying to fix a keyboard you can create more problems than you originally had so it is easier to simply replace the keyboard.

To do this you would have to nearly completely disassemble the laptop.

Here's the hardware maintenance manual for the laptop.

Go to p.43 (49 of 60pdf) to view the procedure to remove the Remove the upper case (with keyboard and touchpad).

Lenovo doesn't supply the keyboard as a separate part. It comes as a complete module with the upper case assembly. You will have to remove the touchpad from your laptop and insert it the new upper case assembly though as it isn't part of the module. You could try sourcing a compatible keyboard only, but this would involve either cutting off the nylon plugs that fix the keyboard to the assembly or drilling out the metal rivets that hold it on, (not sure which method is used in your model). Then you would have to somehow glue the new keyboard back in place.

Also there are 64 different keyboard upper case assemblies available for the laptop. They are country i.e. language, colour and backlit (Y/N) specific, as well. The easiest way to know which is the uppercase assembly for your particular model is to look for the part number located on the underside of the uppercase assembly e.g. 5CB0Z20927 (USA) , 5CB0Y99514 (GER) etc, and search online using the part number to find suppliers.

If it has gotten wet besides having to so the above, you would also have to check if the motherboard is OK and hasn't also been affected e.g. corrosion or other liquid damage