What should I do if my Keurig K-Supreme Plus is only brewing a partial cup?

Power the brewer off, then press and hold the brew button and 12oz button for 5 seconds until water starts dispensing, then release and let the water purge before discarding the contents into the sink. The exit needle may also be clogged and should be cleaned using a straightened paper clip, and if the issue persists after descaling the brewer twice, you should contact Customer Service. (Page 12)