Fax Connection Issue

[Greco14]

My issue is sending a fax whereupon dialing takes place, accepts the fax signal and advises me connection is being made and, after a few seconds, disconnects transmission and returns an error 345 for a communication error. I've tried sending to HP's fax (Edited) as instructed but with the same results. My fax is hooked up directly to a phone wall jack with the original 2-conductor phone wire.  Also, I'm attempting to fax from the printer itself and not the PC monitor.

I don't know if Wi-Fi is involved with faxing but I recently replaced my DSL modem with a Fios 5G wireless. I really don't know if that is part, or, all of my issue. If so, why would that be?

HP's virtual agent is useless in this case. Can anyone offer some resolution to my issue.      

[zoey7886]

@Greco14, Welcome to the HP Support Community!  

Thanks for reaching out about your query regarding the fax connection issue! 

We're thrilled to have the opportunity to assist you and provide a solution.  

The issue you’re facing with your HP OfficeJet Pro 8025e printer when faxing (Error 345) is most likely related to the change from a DSL modem to a Fios 5G wireless connection. Here’s why and how to troubleshoot:

💡 Why the Fios 5G Wireless Change Matters

1. Faxing works over analog phone lines – Traditional fax machines require an analog signal to transmit faxes.
2. Fios and 5G networks are digital – When you switched from DSL (which can work with fax) to Fios 5G, the phone line signal might now be digital, which is incompatible with fax transmission.
3. Signal Conversion Issue – If the Fios line converts the signal from analog to digital, it may create timing issues or signal degradation, leading to Error 345 (communication failure).

Troubleshooting Steps

1. Test the Phone Line Connection

• Ensure the phone line is properly plugged into the LINE port (not EXT) on the printer.
• Plug a standard telephone into the same jack and try to make a call. If the call quality is poor or you can’t connect, the line may not be properly configured for faxing.

2. Lower the Fax Speed

• On the printer's control panel:
  • Go to Settings → Fax Settings → Advanced Fax Settings
  • Lower the fax transmission speed to 9600 bps or the lowest available option.

3. Disable Error Correction Mode (ECM)

• Go to Fax Settings → Advanced Fax Settings
• Disable Error Correction Mode (ECM) – This can help with unstable connections.

4. Use a DSL Filter (Optional)

• Even though you’re no longer using DSL, try connecting a DSL filter to the phone jack. Sometimes Fios or VoIP signals create noise that a filter can help reduce.

5. Test a Different Fax Number

• Try faxing to a different number to rule out issues with the recipient’s fax machine.

6. Consider a Digital-to-Analog Converter

• If the issue persists, you may need a VoIP to analog converter (also called a fax adapter).
• Fios uses a digital signal, so adding a converter will create a compatible analog signal for the fax machine.

7. (Optional) Test on a Landline

• If possible, test the fax machine using a traditional analog landline (if available).
• If it works fine on a landline, then the problem is with the Fios connection, not the printer itself.

🚀 Why Wi-Fi Isn’t Involved

• Faxing doesn’t rely on Wi-Fi — it depends entirely on the phone line connection.
• Wi-Fi is only used for features like scanning to email, printing from the cloud, or HP Smart app controls.

Try these steps and let me know if you need more help! 😎  

Take care, and have an amazing day!  

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Regards,