Hi Error 344,
Is telling you the remote end has hung up the call which means it may not be a fax number (you called a voice line number for example, you can confirm if it as fax by just calling the number on your phone if you hear the whistles of a fax then that's not the cause).
I'm not familiar with the HP model but if it is "Super Group 3" (you can tell this if the transmission speed is capable of above 14.4kbps) and you're trying to call an older fax the remote machine may not be able to recognise the "Calling tone" your machine is sending and so it hangs up. You can try to remedy this by temporarily disabling Error Correction Mode (ECM) in your machines fax set up menu this will disable the Super Group 3 capabilities of the fax and maximum transmission speed will be reduced to the older Group 3 machine. HP website recommends the following:
344, 345, 346, 347, 348, 349 ECM, 350 ECM, 351 ECM, 352 ECM, 353 ECM, 354, 355
- The remote machine failed to respond to a fax command from the local machine because the connection was interrupted. These errors can occur if the phone lines in the area to be faxed are old or there is noise (static on the phone line). Other reasons can include power outages and other power-related problems.
- The call-waiting service can cause this error. The click, heard for an incoming call, is actually a momentary disconnect of the line.
- The remote user pressed the Stop key while the reception was in progress.
- Under rare conditions, incompatibility between the two machines might cause the remote machine to abandon the call.
- Retryt the fax reception at a different time when telephone line conditions have improved. Call the telephone provider if line conditions fail to improve.
- Disable ECM. Errors might still occur, and might result in a degraded image quality on the received page. However, the ability to send the entire document will be improved.
- Try sending at a lower transmission speed.
386, 387, 388, 389, 390, 391, 392, 393, 394, 395
There is too much noise on the line for a valid connection between two fax machines to complete. The noise problem might go away over time.
Retry the fax reception at a different time when telephone line conditions have improved. Call the telephone provider if line conditions fail to improve.