My 6400 printer says it’s busy when I print from my phone or computer.

[Mom148]

My 6400 series printer says it’s busy when trying to print a  pic or a document. It worked fine 2 days ago. It will allow me to print diagnostic pages from my phone through the HP app, but nothing else. I have done a hard restart, removed and added the printer, I have removed and added the app, I have restarted my modem and router, and restarted my laptop and phone. 

[Hawks_Eye]

Hi @Mom148 

Welcome to the HP Support Community! We're here to help you get back up and running.

I’m really sorry this has been so disruptive—especially when your HP 6400 series printer was working perfectly just days ago. That “busy” message can feel like a wall when you’re trying to print something important. 

You’ve already taken all the right steps with resets and reinstallation. Let’s go deeper and restore smooth printing from both your phone and computer.

Step-by-step actions to fix “Printer is busy” error

Clear the print queue

• On your Windows PC:
  • Press Windows + R, type control printers, and press Enter
  • Right-click your HP 6400 printer > See what’s printing
  • Cancel all pending jobs
• On your phone:
  • Open the HP App
  • Tap your printer > Print Queue
  • Cancel any stuck jobs

Power cycle the printer properly

• Turn off the printer and unplug the power cord from the wall
• Wait 60 seconds
• Plug it back in and turn it on—this clears internal memory

Check for firmware updates

• Open the HP App on your PC or phone
• Tap your printer > Advanced Settings > Printer Updates
• Install any available updates

Reset network settings on the printer

• On the printer control panel, go to Settings > Network Setup > Restore Network Settings
• Reconnect using Wi-Fi Setup Wizard
• Ensure it connects to the 2.4 GHz band of your router

Re-add the printer using the HP App

• Remove the printer from the app
• Tap Add Printer, wait for it to appear, and follow the setup steps
• Confirm the printer is listed as Ready and not Busy

Print a test document

• Use the HP App to print a simple PDF or photo
• If successful, try printing from another app or your computer

Let me know if the printer still shows “busy” after these steps or if the issue only affects one device—I’ll guide you further based on what we find. 

You’ve been incredibly thorough, and we’ll make sure your printer responds exactly when you need it.

If my response helped, please mark it as an Accepted Solution! ✅ It helps others and spreads support. 💙 Also, tapping "Yes" on "Was this reply helpful?" makes a big difference! Thanks! 😊

Take care, and have an amazing day!

Regards, 

Hawks_Eye