Pioneer 504CMX - PDP - 50" Plasma Panel Technical Manual page 41

5. Maintenance and Cleaning
e) Replacing the pen tip
If the tip becomes deformed and writing quality deteriorates, replace the tip with one of the two supplied extras.
Note:
Continued use of a worn pen tip may damage the display.
1. Remove the tip.
2. Insert one of the supplied replacement tips.
f) Pen battery life
The battery in the pen has a life of about 20 hours of continuous use (when an alkaline battery is used).
41