HP OfficeJet Pro 8000/8500 Series Printers, black or red streaks

If you see colored streaks, and your printer is not out of ink and is not saying it is in need of a printhead change, then you need to clean the prinhead and do a calibrarte linefeed.

1. on the display, wrench, tools, clean printhead, if thisfixes the problem, then "no" else "yes".
2. if the gradient color blocks prints came out with improper bands, call HP support (may cost money if beyond warranty, you can purchase up to 3 years warranty).
3. Tools, calibrate linefeed.
4. exit the menu.