Clean Printhead HP Officejet Pro 6978
Gather the necessary cleaning materials , and start cleaning. Open the ink cartridge access door. Wait for the peripheral components to remain idle and silent before you proceed. Clean the inner parts of the printer using suitable cleaning equipment. Clean the printhead contacts carefully. Reinsert the ink cartridge into the slot, and then press the ink cartridge until it clicks into place. Repeat the same for another ink cartridge. Close the ink cartridge access door, if opened.