all my prints have faint horizontal lines or gaps in the text, i've done a cleaning cycle but it comes back.

Diagnosis

The presence of persistent horizontal lines or "banding" in the HP Smart Tank 7602 indicates that one or more of the microscopic nozzles in the printhead are partially obstructed. While you have attempted a standard cleaning cycle, these superficial cycles often fail to clear "hard" clogs—where ink has dehydrated into a semi-solid crust—or "air locks," where air bubbles have become trapped in the ink delivery tubes between the tank and the printhead. Because this is a continuous ink system, the ink must travel through long tubes. If the printer sat idle for several weeks, gravity and evaporation can cause ink to recede, leaving a pocket of air. When the printhead fires, it cannot pull a consistent stream of ink, resulting in those characteristic gaps or faint streaks across your text. If the lines appear consistently in the same spot on every page, it is a physical nozzle blockage; if they shift slightly, it is likely an alignment or air-bubble issue.

How to Fix It

To resolve deep-seated clogs and air pockets in the HP Smart Tank 7602, you must perform a sequenced "Power Cleaning" and a manual alignment. Follow these exact steps:

1. Power on the printer and ensure the ink tanks are filled at least halfway. If ink levels are low, the cleaning process may suck air into the system, making the problem worse.
2. On the printer's integrated control panel, navigate to the Setup menu (gear icon).
3. Select Tools, then select Print Quality Tools.
4. Choose Clean Printhead. This is the first stage. Once complete, print a Print Quality Report to see if the gaps persist.
5. If the gaps remain, return to Print Quality Tools and select Second-stage Cleaning (or "Deep Clean" depending on firmware version). This process uses a higher pressure pump to force ink through the nozzles.
6. Immediately after the deep clean, navigate to Setup > Tools > Align Printhead. The printer will print an alignment page. Place this page face-up on the scanner glass, close the lid, and press the Scan button. This recalibrates the nozzle firing timing to eliminate horizontal banding.
7. Print a final test page using "Best" quality settings rather than "Normal" to confirm the lines are gone.

If That Didn't Work

• Manual Printhead Cleaning: If the software fails, remove the printheads from the carriage. Use a lint-free cloth dampened with distilled water (or a dedicated printhead cleaning solution) and gently dab the gold-colored nozzle plate on the bottom. Do not scrub; simply blot until you see a clear "stamp" of ink on the cloth.
• Air Bubble Purge: Open the ink tank caps and close them tightly to ensure a vacuum seal. If you see large gaps in the ink tubes leading to the printhead, you may need to use a syringe (without a needle) to gently pull ink through the printhead intake port to prime the lines.
• Paper Weight Adjustment: If you are using heavy cardstock or non-HP paper, the "lines" may actually be "ink pooling" or "skipping" due to the rollers. Change the paper type in the print dialog to HP Matte or Heavyweight to adjust the printhead height.
• Printhead Replacement: If the nozzles are permanently scorched or clogged with dried pigment that chemical cleaning cannot move, the printheads (which are user-replaceable on the 7602 model) must be replaced. Check for the specific part numbers for the Black and Tri-color heads compatible with the 7600 series.

Heads Up

• Preventative Printing: To prevent future clogs, print at least one full-color page every 7-10 days. This keeps the ink moving and prevents dehydration in the nozzles.
• Ink Quality Warning: Never use third-party "compatible" inks in the Smart Tank 7602. The viscosity of non-OEM ink is often different, leading to frequent air locks and permanent nozzle clogging.
• Avoid Power-Offs: Always turn the printer off using the power button rather than unplugging it from the wall. This ensures the printheads are "parked" in the capping station, which seals the nozzles and prevents them from drying out.
• Cleaning Limit: Do not run more than three deep cleaning cycles in a 24-hour period. Over-cleaning can overheat the printhead elements and waste a significant amount of ink.