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HP DeskJet 3721 Manual — Setup, Troubleshooting & Cartridge Guide

The HP DeskJet 3721 is a compact all-in-one printer designed for home and small office use, offering printing, scanning, and copying capabilities with wireless connectivity. This guide covers complete setup instructions, control panel features, troubleshooting solutions, and cartridge management to keep your printer running smoothly.

Wireless & USB Connectivity Color Inkjet All-in-One HP 65/65XL Cartridges
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Product Setup

1

Load Paper into the Input Tray

Raise the input tray and extender, then insert paper with the short edge down and print side up. Slide the paper-width guide to the right until it stops at the edge of the paper. Pull out the output tray extender and lift the paper catch to complete loading.

2

Install HP 65 or 65XL Cartridges

Open the cartridge access door and wait for the print carriage to move to the center. Remove plastic protective tape from new cartridges, then slide them into the correct slots at a slight upward angle until they click into place. Close the cartridge access door securely.

3

Connect to Your Network

Press the Wireless button on the control panel to activate wireless capabilities. The printer will search for available networks. From your computer or mobile device, connect to your network and follow the on-screen prompts to complete the wireless connection setup.

4

Install Printer Software

Download and install the HP DeskJet 3721 software from HP's website or use the included installation media. On Windows, access the software from Start > All apps > HP. The software provides access to print settings, maintenance tools, and supply ordering options.

info

Pro-Tip: Do not touch the copper-colored contacts or the ink nozzles. Touching these parts can result in clogs, ink failure, and bad electrical connections.

WiFi Connection Guide

router

Wireless Network Connection

Connect the printer to your home or office Wi-Fi network. Press the Wireless button and the Information button together to run the wireless test and print the network configuration page for detailed connection information.

devices

Wi-Fi Direct Printing

Print directly from mobile devices without a router using Wi-Fi Direct. Press the Wi-Fi Direct button to enable this feature, then search for the printer's Wi-Fi Direct name on your device and enter the Wi-Fi Direct password to connect.

Troubleshooting FAQ

Paper Jam in Input or Output Trayexpand_more
Press the Cancel button to attempt automatic jam clearance. If unsuccessful, gently pull the jammed paper from the input or output tray. Check for foreign objects in the paper path and remove them. Reload paper and press the Resume button to continue printing. Do not remove the input tray shield as it prevents debris from entering the paper path.
Cartridge Not Detected or Low Ink Alertexpand_more
If the Ink Alert light is on or ink level icons are blinking, first verify that plastic protective tape has been completely removed from the cartridges. Open the cartridge access door and reinsert the cartridges firmly until they click. If the error persists, remove the cartridges and clean the gold electrical contacts on both the cartridges and printer using a dry, lint-free cloth. Reinstall the cartridges and close the access door.
Poor Print Quality or Streaky Outputexpand_more
Verify you are using original HP cartridges and high-quality paper with the ColorLok logo. Check ink levels—cartridges may be low. Load unused plain white paper and use the printer software to align the cartridges (Windows: Print & Scan > Maintain Your Printer > Align Cartridges). Print a diagnostic page to check for color streaks. If streaks are visible, clean the cartridges through the printer software (Print & Scan > Maintain Your Printer > Clean Cartridges).
Printer Not Printing or Not Respondingexpand_more
Verify the printer is powered on and paper is loaded. Disconnect and reconnect the USB cable if using wired connection, or confirm wireless connection is active. Check that the printer is not paused or offline in Windows (Control Panel > View devices and printers > right-click printer > check Printer menu). Verify the printer is set as default. Restart the Print Spooler service and restart your computer if problems persist. Use HP Print and Scan Doctor utility (Windows only) to diagnose issues.
Wireless Connection Drops or Not Connectingexpand_more
Press the Wireless button and Information button together to print the wireless network test report. Ensure your router is powered on and the printer is within range. Move the printer closer to the wireless router if signal is weak. If the Wireless light blinks with the Wireless Attention icon on, there may be a connection problem—run the wireless test to review the diagnostic report. Check that you are using the correct network password and that the printer's wireless capabilities are enabled.
warning

Important Safety Instructions

  • Always turn off the printer using the Power button and wait until the light goes out to protect cartridges from drying out
  • Do not open or untape cartridges until ready to install—keep protective tape on to reduce ink evaporation
  • Check ink levels regularly using the control panel display or printer software, and keep replacement cartridges available to avoid printing delays
  • Align cartridges quarterly or whenever print quality declines by using the printer software maintenance tools
  • Clean the cartridge contacts with a dry, lint-free cloth if cartridges are not detected, and avoid touching electrical contacts when handling cartridges

Replacement Ink Cartridges

The HP DeskJet 3721 printer uses genuine HP 65 / HP 65XL ink cartridges. Select your cartridge below to purchase replacement cartridges on Amazon:

shopping_cart Buy HP 65 on Amazon shopping_cart Buy HP 65XL on Amazon

Technical Specifications

Feature Specification
ModelHP DeskJet 3721
Function TypeAll-in-One (Print, Copy, Scan)
Cartridge TypesHP 65 Black, HP 65 Tri-Color; HP 65XL Black, HP 65XL Tri-Color
Print TechnologyThermal Inkjet
ConnectivityWireless 802.11b/g/n, Wi-Fi Direct, USB 2.0
Control Panel DisplayLED display with ink level icons, error codes, and wireless status indicators
Paper Sizes SupportedLetter, A4, 4x6 inches, 5x7 inches, envelopes, custom sizes
Power ManagementSleep mode after 5 minutes of inactivity; Auto-Off after 2 hours when not on network
Related ModelsHP DeskJet 3700, 3720, 3722, 3730, 3733
Manual PDFAvailable at http://h10032.www1.hp.com/ctg/Manual/c05152483.pdf