Nakajima wpt-150 electric typewriter brand new was working fine now only printing 1/2 letters (the top 1/2) of each letter whether in lowercase or capitalized.

SOURCE: Does not printer lowercase letter "f"

Do you have another computer to connect this printer to in order to try and recreate this issue? It may help determine if the issue is the printer itself.

SOURCE: Nakajima AE-830

The typewriter is set in P.S. mode instead of 10 or 12. This switch is in lower left corner of keyboard.

SOURCE: Nakajima AX-60

check you type wheel ,and clean your optical reader ,optical reder read`s your typewheel and because of some dirt sometimes printer moves a type wheel one step forward and you get a II.

SOURCE: How to type in capital letters on facit typewriter?

You did not specify if it was a manual or electric or the model, so assuming it is a standard manual or electric machine, push down on the shift key and hold it, then type your letter or letters. If you are typing everything in caps, press the shift lock key.

SOURCE: Here's the problem: it types just fine, but only

Take out the printwheel, manually turn it look for bent or broken spokes on it, or just breplace it.
DickyO