Quote Originally Posted by darry1322 View Post
Dirty coronas and old drums give similar output. Sometimes cleaning the coronas will solve the issue for a while. If cleaning coronas doesn't work then it's time for a new drum.
This is my opinion also. You can try to swap the magenta corona with another color first to see if the defect keeps the same color of if it changes, and then try the same with the drum. Doesn't hurt and it can help you pinpoint the problem before ordering parts.