The error message shows that a printer error has occured. Try the following workaround.
Turn the printer off, and then turn it on again.
If the 49 error returns turn the power off, unplug the power cable, disconnect all network cables, and remove the HP Jetdirect card (or any third-party devices), if installed.
Wait at least 30 seconds before plugging the printer back in directly to a wall outlet. Do not plug the printer into a power strip or a surge protector.
Turn the printer on. If the 49 error returns, turn the power off, and then unplug the printer.
Remove the formatter board.
Check that the parallel I/O board is firmly installed on the formatter board.
Check for any non-HP memory DIMMs. If any extra memory is installed, remove it.
Reconnect the power cord, and turn the power on.
If the 49 error returns, perform a cold reset.
Turn the printer on.
Watch the control panel.
When the memory starts counting, press and hold the green (Select) button.
Continue holding the green (Select) button until the Ready, Data, and Attention lights flash once, and then stay on steady.
Release the (Select) button when the Ready, Data, and Attention light are on steady. The control panel will display SELECT LANGUAGE.
Press (Down Arrow) button once. The control panel will display COLD RESET.
Press (Select). The printer will perform a cold reset and then continue its power-on sequence.
If the 49 error returns, contact an HP-authorized service or support provider.
Hope this resolves the issue that you are experiencing.