@jimwinder1320 … please upload an example of what you are seeing. this guide will help:
[guide|21499]
self cleaning options are a great maintenance feature to utilize before these types of issues occur. this type of fault is usually indicative of a clogged ink jet/printer head. after time of use and prolonged times of unuse without servicing with self clean functionality, the ink can clog and harden to where the self clean option does not do the job. in this case, you will want to get to the heads and inspect visually and soak with isopropyl alcohol to loosen and hardened ink or debris.
here is a guide that will help you out:
https://www.youtube.com/watch?v=TSao7pWBpnc
hope this helps. dont forget to upload the photo example so we can confirm or get another idea of what the issue may be. although this symptom is typically caused by what was described above, there may be other issues.