Your HP Smart Tank 5101 has flashed a "not recognized" style fault, and you have probably gone hunting for a cartridge to reseat or swap. Here is the important part. This printer does not use ink cartridges at all, so a literal cartridge-not-recognized error does not apply to it. The Smart Tank 5101 is a continuous-ink-tank printer that pours ink into built-in refillable tanks and prints using two user-replaceable printheads, so what you are actually seeing is a printhead error.
That distinction matters, because the fix is completely different from the cartridge guidance you may have found for other HP models. A printhead that is not detected, not seated correctly, or starting to fail is what triggers this fault on the 5101. The fixes below move from the quickest, safest checks to the deeper resets and the support path, so start at the top and stop as soon as printing returns to normal.
Confirm It Is a Printhead Error and Check Ink and Paper First
Before touching anything, look at the control panel to see which printhead is actually flagged. If the Tri-color printhead icon is blinking, the tri-color printhead caused the error. If the Black printhead icon is blinking, the black printhead caused the error. If both icons blink, both printheads caused the error. Knowing which one is involved tells you exactly which printhead to reseat later.
Next, handle two simple requirements that quietly block clearing this error. Make sure the ink tanks are at least half full and that plain paper is loaded in the input tray. Low ink or an empty tray can trigger or prevent the printer from clearing a printhead error, so topping up and reloading is genuinely a fix, not just housekeeping.
Power-Cycle the Printer to Clear a Transient Fault
If lights are blinking or behavior is erratic, a clean power reset clears many temporary errors before you do anything more involved. This is the lowest-risk step on the list, and it often resolves a printhead that simply failed to register at startup.
- 1.Press the Power button to turn off the printer. If it does not turn off, disconnect the power cord.
- 2.Unplug the power cord from the power source.
- 3.Wait 60 seconds.
- 4.Reconnect the power cord directly to a wall outlet and to the printer.
- 5.Turn on the printer.
Connecting straight to a wall outlet, rather than through a surge strip or extension, helps rule out power-delivery issues during the restart. Once the printer is back on, check whether the printhead icon has stopped blinking.
Reseat the Printhead That Triggered the Error
If the error persists, the flagged printhead may simply be seated poorly. Reseating it re-establishes the electrical contact between the printhead and the carriage, which is one of the most common cures for a printhead-not-detected fault. Handle printheads by the sides, keep them upright to prevent ink leaking, and never touch the copper-colored contacts or the ink nozzles.
- 1.Turn on the printer and close the output tray extender if it is open.
- 2.Open the front door and wait until the carriage moves to the center and stops.
- 3.Make sure the printhead carriage latch is closed. If it is open, push down to close it, close the front door, then try to print.
- 4.If the latch is closed, press and release the blue latch to open the printhead cover.
- 5.Remove the printhead that caused the error and set it aside upright on a protected surface.
- 6.Make sure the plug on top of the printhead has been removed and the tape from the printhead contacts has been removed.
- 7.Slide the printhead into its slot and gently push at a slight upward angle until it snaps into place.
The snap into place is what confirms the printhead is fully seated, so do not stop short of it. Close everything up and run a test print to see whether the error has cleared.
Run a Print Quality Diagnostic and Clean the Printhead
If the printhead is recognized but pages come out poorly, the issue is print quality rather than detection, and a diagnostic plus cleaning is the right move. On the Smart Tank 580, 590, 5000 or 5100, press and hold the Color Copy button for three seconds to print a Print Quality Diagnostic Page. Review the test patterns for missing colors, fading, and white lines.
The recommended way to clean is through the companion app. Load plain white paper, open the HP app, click the image of your printer to open the settings and management tools, then run the printhead cleaning.
You can also clean directly from the control panel if you prefer not to use a computer or phone. Press and hold the Power button for more than 4 seconds, press the Color Copy button two times, then release the Power button to begin cleaning. Wait at least 30 minutes before cleaning the printhead again, because cleaning consumes ink and back-to-back cycles can do more harm than good.
Fix a Stuck Queue or Offline Status on a Connected Computer
Sometimes the printer is fine and the computer is the holdup, showing the device as offline or jamming up behind a stuck job. On Windows, search for and open Printers and scanners, select your printer, and click Open queue. Make sure Pause Printing and Use Printer Offline are not selected. If a checkmark displays next to either, select the item to clear it, then right-click any stuck print job and click Cancel.
If jobs still will not clear on Windows, reset the print spooler. Search for and open Services, right-click Print Spooler and click Stop, then in File Explorer browse to C, then Windows, then System32, then spool, then PRINTERS, and delete all files in the PRINTERS folder. Return to Services and start Print Spooler again.
On a Mac running macOS 12 or later, if the printer is stuck or unavailable you can fully reset the printing system. Open Spotlight, search for and open Printers and Scanners, right-click or Control-click in the Printers list, and select Reset printing system. Restart the printer, then click Add Printer, Scanner, or Fax, select your printer, and click Add. Note that this removes all printers and clears saved print settings and jobs, so you will need to re-add any other printers afterward.
Update or Reinstall the Printer Software
Corrupted or outdated drivers can cause communication and recognition errors that look like a hardware fault. Download the latest drivers and the HP app for the Smart Tank 5101 from HP's official support website, and avoid third-party download sites that may bundle the wrong package.
If the problem continues after a power cycle and a reseat, a clean removal and fresh reinstall of the printer software often restores normal communication. Reinstalling the current software clears out the outdated or damaged files that were getting in the way, then lets the printer be detected cleanly the next time you print.
Reset the Network Connection If the Printer Will Not Appear
If the printer simply will not connect or show up in the HP app, putting it back into Wi-Fi setup mode gives you a clean start. On the Smart Tank 5100, press and hold the Information button for 5 seconds until the control panel buttons light up. Then press and hold the Wireless and Cancel buttons at the same time for 5 seconds until the Wi-Fi light blinks blue.
Within two hours, return to the HP app to find and add your printer. Keep the printer on the same network as your phone or computer during setup, and if your router broadcasts separate bands, connect it to the 2.4 GHz network.
Restore Factory Defaults, Then Contact HP for Service
As a last on-device step, restoring factory defaults wipes lingering software glitches that survived the earlier resets. This clears your saved network connection and any custom settings, so you will need to set the printer up again and reconnect it to Wi-Fi afterward. On the Smart Tank 5100, press and hold the Resume and Black Copy buttons at the same time and, without releasing them, turn on the printer. Wait at least 5 seconds, then release the buttons.
If a printhead error still persists after reseating, cleaning, and resetting, the printhead itself may be failing and need replacement. At that point, replacing the affected printhead or contacting HP support for service is the right call, since the remaining fault is hardware rather than a setting you can change.
Frequently Asked Questions
Does the HP Smart Tank 5101 use ink cartridges?
No. The Smart Tank 5101 is a continuous-ink-tank printer, so ink is poured into built-in refillable tanks for Cyan, Magenta, Yellow, and Black from bottles. Printing is handled by two user-replaceable printheads, a black printhead and a tri-color printhead, which is why a cartridge not recognized error does not literally apply to this model.
How do I know which printhead is causing the error?
Check the control panel icons. A blinking Tri-color printhead icon points to the tri-color printhead, a blinking Black printhead icon points to the black printhead, and both icons blinking means both printheads are involved.
How often can I clean the printhead?
Wait at least 30 minutes between printhead cleaning cycles. Cleaning uses ink, so running repeated cycles too quickly is wasteful and can work against you. Give the first cleaning time to take effect before trying again.
What should I check before troubleshooting a printhead error?
Make sure the ink tanks are at least half full and that paper is loaded in the input tray. Low ink or an empty tray can trigger the error or stop the printer from clearing it, so both need to be sorted before the other fixes will work reliably.
What does it mean if the printhead error will not clear?
If a printhead error persists after reseating, cleaning, and resetting, the affected printhead may be failing and need replacement. At that point, replacing the printhead or contacting HP support for service is the most reliable path, since the remaining fault is hardware rather than a setting you can change.
