HP LaserJet M234sdw couldn't connect scanner even though it had connected previously

[Tara1233TaR]

HP LaserJet M234sdw couldn't connect scanner even though it had connected previously. The error message is "Couldn't Connect to Scanner.  HP Smart cannot scan fro this printer. Either no scanner was detected or HP Smart is not compatible with the scanner in this printer. Please help.

[A_Gayathri]

Hi @Tara1233TaR,

Welcome to The HP Support Community.  

Thank you for posting your query, I will be glad to help you.

I understand the error message you're encountering with your HP LaserJet MFP M234sdw Printer typically indicates a communication issue between the scanner and the HP Smart app. Here's how you can troubleshoot this problem:
 

1. Restart Devices:

• Restart Printer: Turn off the printer, unplug it from the power source, wait for 60 seconds, and then plug it back in and turn it on.
• Restart Computer: Restart the computer to ensure there are no background processes affecting the connection.
• Restart Router: If the printer is connected via WiFi, restart your router to refresh the network connection.

2. Check the Network Connection:

• Wireless Connection: Ensure that both the printer and the computer are connected to the same WiFi network. A mismatch in the network connection can cause this error.
• Wired Connection: If you're using an Ethernet cable, make sure it’s securely connected to both the printer and the router.

3. Update or Reinstall HP Smart App:

• Update: Ensure that you have the latest version of the HP Smart app installed.
• Reinstall: If the app is up to date and the issue persists, uninstall the HP Smart app from your computer, restart your computer, and then reinstall the app from the Microsoft Store or HP’s official website.

4. Check Scanner Drivers:

• Update Drivers: Go to the HP support website, search for your printer model, and download the latest drivers for the scanner. Install any updates if available.
• HP Print and Scan Doctor: Download and run the HP Print and Scan Doctor tool to automatically diagnose and fix issues related to scanning.

5. Verify Windows Services:

• Windows Image Acquisition (WIA): Ensure that the Windows Image Acquisition service is running:
  1. Press Windows + R, type services.msc, and press Enter.
  2. Locate "Windows Image Acquisition (WIA)" in the list.
  3. Ensure the service is running and set to "Automatic." If it’s stopped, right-click it and select "Start."

6. Firewall/Security Software:

• Check Firewall Settings: Temporarily disable any firewall or antivirus software to check if they are blocking the HP Smart app from accessing the scanner. If disabling resolves the issue, configure the software to allow HP Smart.

7. Try a Different Scanning Method:

• Windows Fax and Scan: Open the "Windows Fax and Scan" app (found in the Start menu) and attempt to scan using this tool.
• HP Scan and Capture: Try using the "HP Scan and Capture" app as an alternative to the HP Smart app.

8. Reset the Printer:

• Perform a factory reset on the printer to restore it to its default settings, then set it up again. Be aware that this will remove any customized settings, so make sure to note any specific configurations before resetting.

Refer to this document:  HP LaserJet MFP M234sdw Printer User manual

I hope this helps. 

Take care and have a good day.

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