Hi Headbro,
I am sorry to hear you had no luck with phone support. I would be happy to help. I suggest we run through the print quality troubleshooting in order to resolve the issue.
HP Photosmart C4680 All-in-One Printer Troubleshooting Print-Quality Issues
HP Officejet J4680 All-in-One Printer Poor Quality Black Text
If the solutions offered in the document do not resolve the issue, please post back and let me know which 4680 you have, thanks.