Paper Mismatch & Setup Not Connecting To Internet Issue

[Nouman6]

Hi! I have been trying to print a document from my HP Printer Deskjet - 4123. I also tried connecting it to the internet with setup, but it always failed in the state 'printer is connecting to the network'. Both worked earlier fine and connected to the internet easily from phone or computer. It also printed coloured documents, but after a time, it stopped working; only the scanner options(glass flatbed & document feeder) worked perfectly from the USB.  I tried many things, reset the wifi adapter, factory reset the whole printer, and also tried cleaning the paper size sensor, and at last, I also tried changing paper size from letter to A4 anywhere(2-3 Places) in the control panel. Please see to it as soon as possible. 

[Hawks_Eye]

Hi @Nouman6 

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

Thank you for sharing the details of the issue. I understand that your HP DeskJet 4123 is showing paper mismatch errors and is unable to connect to the network during setup, even though scanning works fine via USB. 

Let’s go through the steps to address both concerns.

Paper Mismatch Issue

Check Paper Size Settings in HP App and Printer Driver

• Open the HP App on your Windows or Mac computer.
• Go to Print Settings and ensure the paper size matches the paper loaded in the tray (A4 or Letter).
• In the print dialog box on your computer, confirm the same paper size is selected.

Load Paper Correctly

• Remove all paper from the input tray.
• Fan the stack to prevent sticking, then reload it.
• Adjust the paper guides so they lightly touch the edges of the paper without bending it.

Clean the Paper Path

• Power off the printer.
• Remove any jammed or misaligned sheets.
• Ensure the tray is free of dust or debris.

Wireless Setup Not Connecting

Restart Devices

• Restart your printer, router, and computer.
• Ensure the router is working and broadcasting on 2.4 GHz (the DeskJet 4123 does not support 5 GHz).

Use HP App for Setup

• Open the HP App on your Windows or Mac system.
• Select Add Printer → Set up a new printer.
• Follow the guided steps to connect the printer to Wi-Fi.

Manual Wireless Setup Mode

• On the printer, press and hold the Wireless and Cancel buttons together until the Power light blinks.
• This enables setup mode.
• In the HP App, search for the printer and connect it to your Wi-Fi network.

Check Router Settings

• Ensure MAC address filtering is off.
• WPA2 security should be enabled.
• If your router has both 2.4 GHz and 5 GHz bands, connect only to 2.4 GHz.

Summary

• Align paper size in both the HP App and printer driver.
• Reload paper properly and clean the tray.
• Restart devices, use the HP App for setup, and confirm router settings.
• Use manual wireless setup mode if automatic connection fails.

Take care, and have an amazing day!

Regards, 

Hawks_Eye