Make sure you purchase the right ink cartridges for your specific printer and printer region or have your old ones refilled. Cartridges are not compatible between different brands, and often not within the same brand. HP often designs its inkjet hardware to use country-specific consumables. When you unbox a new HP inkjet printer and set it up, you install a set of ink tanks that ship with the printer. As you turn on the device and get ready to use it, an initialization sequence localizes it to the country associated with the ink cartridges you installed. HP recommends that you use original HP ink cartridges.
XL (Extra Large) cartridges cost more but do provide better value in the long run. They will be able to print at least double the pages of a regular cartridge. Our advice is that if you print often, go with XL. However, ink can dry up. So if you are not a frequent printer, go with the regular cartridges.
You can check the estimated ink levels from the printer software, Control-panel, or the embedded Web server. The icon below on the Control-panel displays a screen where you can see information about the ink cartridges, including fill levels. This icon has a red border when an ink cartridge needs attention. Ink level warnings and indicators provide estimates for planning purposes only. When you receive a low-ink warning message, consider having a replacement cartridge available to avoid possible printing delays. You do not need to replace cartridges until prompted to do so.
For your US HP Officejet Pro 8500A Plus e-All-in-One you need HP 940 Black (XL) and HP 940 Cyan/Magenta/Yellow cartridges. There are also Combo Packs (4 cartridges in one pack) available, like the HP 940XL Black Ink Cartridge and HP 940 Colors Standard Yield Cartridges Four Color Combo Pack.
For your European and UK HP Officejet Pro 8500A Plus e-All-in-One you need HP 940 Black and HP 940XL Cyan/Magenta/Yellow cartridges. There are also Combo Packs (4 cartridges in one pack) available, like the HP 940XL 4-pack High Yield Black/Cyan/Magenta/Yellow Original Ink Cartridges (C2N93AE).
Try Amazon's ink selector tool to find compatible ink cartridges for your printer.
Replace the ink cartridges
2. Load plain unused Letter or A4 white paper in the input tray.
Align the printhead only if necessary.
The printer automatically aligns the printhead during the initial setup. You might want to use this feature when the printer status page shows streaking or white lines through any of the blocks of color or if you are having print quality issues with your printouts. You can align the printhead from the printer’s control panel, from the Toolbox (Windows) or HP Utility (OS X), and from the embedded web server (EWS).
– From the Control panel: Touch right arrow , touch Setup, touch Tools, and then select Align Printer.
– From the Embedded Web server: Click the Settings tab, click Device Services in the left pane, select Align Printer from the drop-down list in the Print Quality section, and then click Run Diagnostic.
– From the HP Software (Windows): Open the HP software that was included with the printer. Click Printer Actions, click Maintenance Tasks, and then click Align Printheads.