According to this document, error 344 may be caused due to following reasons:
Check for poor line conditions. Older phone lines, static on the line, power brownouts, or other power-related problems can cause communication failures. Call the telephone provider if line conditions fail to improve.
Stop key was pressed on the receiving fax machine before the fax completed. Contact the person receiving the fax to see if they are cancelling the transmission. If not, send the fax again but at a slower transmission speed.
Call waiting service made a click sound that is heard for an incoming call, momentarily disconnecting the fax call. Disable error correction mode (ECM) if necessary.
As the error occurs only while using the feeder, let us try these steps:
Reset the printer
With the printer turned on, disconnect the power cord from the rear of the printer.
Wait at least 60 seconds.
Reconnect the power cord to the rear of the printer.
Turn ON the printer, if it does not automatically turn on.
Wait until the printer is idle and silent before you proceed.
Note: HP recommends connecting the printer directly to a wall outlet rather than a surge protector or a power strip.
Update the printer firmware
Click here to download and install the latest firmware from your computer.
Click here to know different methods of updating printer firmware.
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