my eco tank's black ink level shows full but it's printing really faded or not at all, other colors are fine.

Diagnosis

The issue is a failure of ink delivery, specifically an air lock or a "dry" segment within the black ink delivery tube. Even though the external tank is full, the ink is not reaching the print head nozzles. This typically happens if the printer sat idle for several weeks, if the printer was moved or tilted, or if a "Power Cleaning" cycle was run multiple times, which can actually suck air into the lines if the tank levels were too low during the process. You can confirm this by performing a Nozzle Check. If the grid for Cyan, Magenta, and Yellow is perfect, but the Black grid is completely blank or shows only a few faint horizontal streaks, the problem is localized to the black channel. If you look closely at the transparent tubes leading from the tanks to the print head carriage, you will likely see gaps of air or "bubbles" in the black line while the color lines remain solid and saturated.

How to Fix It

To resolve this, you must force the ink through the system using the internal pump. Follow these exact steps:

1. Ensure the printer is on a completely level surface and that the ink tanks are filled at least halfway to avoid sucking air during the process.
2. On the printer's LCD control panel, navigate to Settings > Maintenance.
3. Select Power Cleaning. This is a more aggressive cycle than a standard head cleaning; it uses a high-pressure pump to pull ink from the tanks, through the dampers, and into the print head.
4. The printer will prompt you to confirm that the ink tanks are full. Select Yes.
5. Wait for the process to complete. This usually takes 10 to 15 minutes. Do not turn off the printer or open the scanner lid during this time, as it can break the vacuum seal.
6. Once finished, print a Nozzle Check pattern. If the black is still faded, wait 12 hours to allow any remaining air bubbles to rise and dissipate naturally before attempting one more Power Cleaning cycle.

If That Didn't Work

• Manual Syringe Priming: If the Power Cleaning fails, the air lock is too severe. You will need to open the printer cover, move the print head carriage to the center, and remove the ink dampers (the small plastic cartridges sitting atop the print head). Using a 10ml medical syringe without a needle, insert the tip into the black damper's outlet port and gently pull the plunger back to suck ink from the tank into the damper. This removes the air gap manually.
• Print Head Soaking: If the ink is flowing but the output is still faded, the black nozzles are likely dried shut. Fold a piece of heavy-duty paper towel into a thin strip, dampen it with a mixture of 50% distilled water and 50% isopropyl alcohol, and place it in the print head path. Manually slide the print head over the damp towel and let it sit for 4 hours to dissolve the dried ink crust.
• Transport Lock Check: Ensure the printer is not in "Transport Mode" or that any shipping tape remnants are not obstructing the ink flow paths. Check the waste ink pads at the bottom; if they are overflowing, the pump cannot create the vacuum necessary to pull ink from the tanks.

Heads Up

• Avoid Over-Cleaning: Do not run the "Power Cleaning" cycle more than twice in a 24-hour period. Doing so can overheat the print head and prematurely fill the waste ink maintenance box, which will lock the printer until the box is replaced.
• Ink Quality: Only use genuine Epson 522 ink. Third-party inks often have different viscosities that can cause the dampers to clog or air bubbles to form more frequently.
• Preventative Maintenance: To prevent future air locks, print at least one full-page black document every two weeks. This keeps the ink moving and prevents the nozzles from drying.
• Tank Levels: Never let your ink levels drop below the lower line on the tank. If the pump sucks air because the tank was empty, you will almost always have to perform a manual prime to fix it.