Unable to Connect to Network, Support Says Serial Number Invalid

[jessicaw3]

I got a new Xfinity router and my printer will not connect to it. I've tried restarting everything, running the Wireless Setup Wizard multiple times, adding the printer's MAC address manually to the router settings. I tried to contact HP support but when I enter the serial number — clearly labeled as "Serial No." on the back of the printer, without any characters that could be ambiguous — it says it's not a valid serial number.

[VikramTheGreat]

Hi @jessicaw3,

Welcome to the HP Support Community.
 

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

I can imagine how frustrating this is: new router, printer won’t connect, and even HP’s support portal rejects your serial number. Let’s tackle this step by step:

Why the Printer Won’t Connect

When you switch to a new router (like Xfinity), common issues include:

• Printer still trying to connect to the old SSID.
• Router using 5 GHz only (HP printers often need 2.4 GHz).
• Security settings (WPA3 or MAC filtering) are blocking the printer.

Fix Connectivity

1. Reset Printer Network Settings
   • Touchscreen models:
     Setup → Network Settings → Restore Network Defaults.
   • Button-only models:
     Hold Wireless + Cancel for 5 seconds until the lights blink.
2. Reconnect via Wireless Setup Wizard
   • On printer:
     Setup → Network → Wireless Setup Wizard → Select your new SSID → Enter password.
3. Ensure Router Settings
   • Enable 2.4 GHz band (Xfinity often defaults to combined SSID—split if needed).
   • Disable MAC filtering temporarily.
   • Use WPA2 security, not WPA3.
4. Use the HP App for Setup
   👉 HP App – For HP Printers, Laptops, and Tech Accessories | HP® Official Site
   • Open app → Add Printer → Follow prompts.

Serial Number Issue

• HP serial numbers are usually 10 characters (letters + numbers).
• Common mistakes: 
  • Confusing “0” (zero) with “O” (letter O).
  • Using the product number instead of the serial number.
• Check: 
  • Printer back panel.
  • Inside cartridge access door.
  • HP Smart app (once connected).

👉 If still rejected, use HP’s Auto Detect Tool: HP Detect My Device | HP® Customer Support

I hope this helps.

Take care and have an amazing day!
 

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Regards,

VikramTheGreat

[jessicaw3]

It was the WPA setting. I ended up having to revert to an older router that would allow a WPA2 setting, since my printer couldn't do the WPA3 setting.

I still don't know what to do about the serial number. It's clearly labeled "Serial No." and there are no 0s or Os in the number or other characters that could be confused. The Auto Detect Tool downloads an exe file but I have a Macbook.

[VikramTheGreat]

Hi @jessicaw3,

Thank you for getting back and letting me know.

Please share the image of the Serial number found on the printer in a private message so I can try to locate and get all the help.

Keep me posted

Regards
VikramTheGreat