HP OfficeJet 7720 Says “Not Designed for Continuous Ink System”? Here’s What That Really Means

Question:

My HP OfficeJet 7720 printed 20,000 pages, and now I’m getting a message that says, “This printer is not designed for a continuous ink system.” Do I need to replace the printhead to fix this, or is there another solution?

Answer:

What Does the “Not Designed for Continuous Ink System” Error Mean?

This alert on the HP OfficeJet 7720 doesn’t necessarily mean something is wrong with the printhead, nor does it directly relate to the number of pages you've printed. Instead, this message typically appears due to a cartridge-related issue, especially when using non-OEM cartridges, refillable ink tanks, or third-party Continuous Ink Systems (CIS).

The printer's firmware is designed to detect inconsistencies in cartridge behavior. When it sees a mismatch in ink delivery or chip communication, it throws this warning as a protective measure.

Most Common Cause: Faulty or Incompatible Cartridge

In most cases, the culprit is a defective ink cartridge—also called an "ink box" in HP terminology. This could be due to:

• A damaged or misread chip on the cartridge

• An air bubble or blockage in the ink line (for CIS setups)

• An aftermarket cartridge that HP's firmware now blocks after a recent update

Fortunately, you do not need to replace the printhead to resolve this issue.

How to Fix It

Step 1: Use HP Smart App to Pinpoint the Problem

The easiest way to find the faulty cartridge is to:

• Open the HP Smart app on your computer or mobile device.

• Navigate to the supplies status section.

• Identify which cartridge is not being detected or shows abnormal readings.

This method is beneficial if all four cartridges appear full but the error still pops up.

Step 2: Replace Only the Problem Cartridge

Once you've identified the affected cartridge (most often it's one of the colors rather than black), replace just that one with a new or OEM-compatible cartridge. Ideally, use a genuine HP cartridge to eliminate compatibility issues during diagnostics.

If you’re using a refillable CIS setup, try the following:

• Reseat the cartridge chip or ink tank.

• Clean the chip contacts with isopropyl alcohol and a lint-free cloth.

• If the message persists, swap in an OEM cartridge temporarily to reset the error.

Step 3: Restart the Printer

After installing a known-good cartridge, restart the printer. The warning message should disappear, and printing should return to regular operation.

Is It a Firmware Trap?

Yes, it can be. HP has pushed firmware updates in the past that block third-party ink chips, especially in models like the 7720 that support high-volume printing. If you've recently updated your printer firmware, this could have triggered the warning.

If that’s the case:

• Check your cartridge vendor for firmware-specific chip versions.

• Avoid automatic firmware updates in the future to preserve compatibility with CIS setups.

We’re Here to Help—But Hands-On Issues May Require Service

Solving printer problems like this often involves checking physical components, firmware compatibility, and ink delivery systems—all of which are hard to diagnose remotely. Because of that, we’re unable to provide individual repair support or live troubleshooting. However, we do offer in-person diagnostics and repairs at our facility:
Printer Repair Service
(https://bchtechnologies.com/printer-repair-service)

Please note that we operate on a first-come, first-served basis, and depending on volume, it might take a few weeks before we can get to your printer. Our service covers both full-printer diagnostics and specific component repairs. That said, we acknowledge that our pricing may not always be the most economical, so we always encourage customers to begin with DIY options first.

You can find many of those solutions right on our YouTube channel (https://youtube.com/@bchtechnologies). Use the search bar next to the “About” section to find specific videos related to HP OfficeJet errors, chip issues, or CIS compatibility. We've created hundreds of videos over the years, and the search function will help you find the most relevant content quickly.

Thanks again for your question and for being part of our community. We wish you the best in getting your HP 7720 back up and running smoothly, without annoying cartridge warnings!