You hit print on your HP OfficeJet Pro 9120e expecting crisp text and clean color, but the page comes out faded, streaked, or missing a color entirely. Print quality problems on this all-in-one almost always trace back to a handful of fixable causes, from a low cartridge to a clogged printhead to a setting that quietly switched on the wrong paper type. The good news is that the 9120e is a removable-cartridge inkjet, so the standard cleaning, alignment, and cartridge-replacement remedies all genuinely apply here. Work through the fixes below in order, because the easiest and safest ones come first and the reset and support paths are saved for last. Most faded or streaked pages clear up well before you reach the bottom of the list.
Start With the Cartridges and Ink Levels
Faded output, a missing color, or generally low-quality printing is most often caused by a cartridge that is low, empty, or not genuine. Open the HP app (formerly called HP Smart) or use the printer's control panel to check the estimated ink levels, and replace any cartridge that is running low or showing empty. Estimated levels are a guide rather than an exact gauge, so a color that prints weakly is worth replacing even if the meter still shows a little ink.
This printer uses HP 937 or HP 937e Original Ink Cartridges. HP recommends genuine HP supplies and states that it cannot guarantee print quality with non-HP or refilled cartridges. If you chose HP+ during setup, the printer requires Original HP ink for its entire lifetime, so a third-party cartridge can stop it from printing correctly at all.
Rule Out the Paper and Quality Settings
Before you touch any maintenance routine, confirm the page itself is not the problem. Use clean, plain paper (ColorLok paper for documents, HP Advanced Photo Paper for photos), because some papers absorb ink poorly and produce faded or smeared results. Damp, dusty, or curled sheets can also drag ink across the page, so load a fresh stack if you are unsure.
Next, check the settings for the job you are printing. In the application you print from, go to File > Print > Options/Preferences (or the Paper Type/Quality or Media & Quality menu) and confirm the paper type, paper size, color, and quality settings all match what you are actually printing. A mismatch here, such as a photo printed on a "plain paper, draft" setting, can look like a hardware fault when it is not.
Print a Diagnostic Report and Clean the Printhead
If the basics look right and the output is still poor, run the printer's built-in cleaning cycle, which also prints a diagnostic page you can examine. On the printer control panel:
- 1.Swipe down to open the dashboard (or swipe the display).
- 2.Touch Setup.
- 3.Touch Printer Maintenance.
- 4.Touch Clean Cartridges.
A Print Quality Diagnostic report prints out, so look it over carefully for gaps, streaks, or missing colors. If quality is still poor, touch Proceed to run the next cleaning stage; the printer offers up to three stages. If the printhead is badly clogged, wait 30 minutes before running all three levels again, which gives stubborn dried ink time to soften. The exact wording on screen can vary slightly with the printer's firmware version, but the path through the maintenance menu stays the same.
Align the Printhead for Sharper Output
Cleaning clears clogs, but it does not fix misregistration, slight blurriness, or banding and line patterns. Those symptoms call for an alignment instead. Load plain white paper first, then on the control panel:
- 1.Swipe down on the control panel to open the dashboard.
- 2.Touch the Setup icon.
- 3.Touch Printer Maintenance.
- 4.Touch Align Printhead.
The printer prints and reads an alignment page, then recalibrates so colors and edges land where they should. Run this whenever cleaning improves the page but text or lines still look slightly off.
Replace the Cartridge That Keeps Failing
Sometimes the diagnostic report still shows defects even after a thorough cleaning and a fresh alignment. When that happens, HP's guidance is to replace the affected cartridge, even if it is not reporting low on ink.
Use a genuine HP 937 or HP 937e cartridge as the replacement. A cartridge can develop a fault or a partially dried nozzle area that no cleaning cycle recovers, and swapping it out is the most direct fix for a single color or channel that refuses to print cleanly.
Run Diagnose & Fix and Clear Any Paused or Offline State
Print problems are not always inside the printer. A stuck spooler, a paused queue, or an offline status on your computer can degrade or block output, and the HP app can resolve those automatically.
On Windows, open the HP app and click the Diagnose & Fix icon in the bottom-left corner, then click Start. On macOS, select your printer, click Printers in the top menu bar, then choose Diagnose & Fix and click Start. Do not close the app while it runs. The tool clears stuck or paused print jobs, brings an offline printer back online, fixes spooler and port errors, and on Windows installs available driver updates.
You can also check this manually on Windows: open the print queue and make sure Use Printer Offline and Pause Printing are not checked, clicking to clear any checkmark you find.
Update the Firmware and Reinstall the Driver
Outdated firmware or a damaged driver can cause inconsistent print quality, so keep both current. To update firmware from the control panel, go to Setup > Printer Maintenance > Update the Printer (or on some firmware versions, Setup > Tools > Update the printer > Check Now). Never power off the printer during a firmware update, because interrupting it can leave the printer unable to start.
For the driver, install the HP app from your device's app store, which installs the needed driver automatically. You can also download the latest driver and firmware from HP's official support site.
Clear a Stuck Queue or Reset the Printing System on Your Computer
If jobs are jamming up or printing badly and Diagnose & Fix did not clear them, you can reset the print pipeline at the operating-system level.
On Windows, turn off and unplug the printer, then:
- 1.Open Services.
- 2.Right-click Print Spooler and choose Stop.
- 3.Delete all files in C:\Windows\System32\spool\PRINTERS.
- 4.Restart the computer.
- 5.Reconnect and turn the printer back on.
On macOS, open Printers & Scanners, Control-click in the printers list, and choose Reset printing system. Be aware this removes all printers and saved settings on the computer, so you must add the printer again afterward. If you prefer a lighter touch, select the printer, choose Remove Printer, then use Add Printer, Scanner, or Fax to re-add it.
Restore Factory Defaults, Then Reach HP Support
If nothing above resolves the print quality, restoring the printer's defaults is the last self-service step. This clears your custom settings, including the network and Wi-Fi configuration, so you will need to set the printer up and reconnect it afterward. From the control panel, touch Setup (swipe down to open the Dashboard first if needed) > Tools or Printer Maintenance > Restore > Restore Factory Defaults > Yes. The printer restarts automatically.
You can also do this through the Embedded Web Server (EWS). Type the printer's IP address into a browser to open the EWS, click the Settings or System tab, then under Restore Defaults click Restore Factory Defaults > Yes. The same data-loss warning applies, so expect to reconfigure the printer once it restarts.
If print quality still fails after a reset and after replacing cartridges with genuine HP supplies, contact HP support. At that point the printhead hardware may need service, which is beyond what menu fixes can address.
Frequently Asked Questions
Which cartridges does the HP OfficeJet Pro 9120e use?
It uses HP 937 or HP 937e Original Ink Cartridges. HP recommends genuine HP supplies and states it cannot guarantee print quality with non-HP or refilled cartridges, and if you enabled HP+ at setup, the printer requires Original HP ink for its lifetime.
How many times can I run the printhead cleaning cycle?
The Clean Cartridges routine offers up to three cleaning stages; touch Proceed to advance to the next stage if quality is still poor. If the printhead is badly clogged, wait 30 minutes before running all three levels again.
What is the difference between cleaning and aligning the printhead?
Cleaning clears clogs that cause gaps, streaks, or missing colors, while alignment fixes misregistration, slight blurriness, or banding and line patterns that cleaning alone does not resolve. If output improves after cleaning but text or lines still look slightly off, run Align Printhead.
Will restoring factory defaults erase my settings?
Yes. Restoring factory defaults returns the printer to its original settings and clears your custom configuration, including the network and Wi-Fi setup, then the printer restarts automatically and needs to be set up again. If you reset the printing system on macOS instead, that removes all printers and saved settings on the computer, so you will need to add the printer again there too.
Can I print from my phone with this printer?
Yes. The 9120e supports mobile printing through Apple AirPrint on iOS and iPadOS, and through Mopria or the HP app on Android, alongside its dual-band Wi-Fi, Ethernet, and USB connections.
