The short version
- 01Turn the printer off and then on, which clears most intermittent 49 errors.
- 02Unplug the network and USB cables, then power on with nothing connected.
- 03Remove any surge protector and plug the printer directly into the wall socket.
- 04Check whether the printer returns to the Ready state on its own.
- 05Print an event log to see how often the error is actually occurring.
- 06Contact HP if it will not reach Ready, since that is a service case.
Raw message
49.WX.YZ Error Turn off then on
Likely causes
- A firmware communication error, which is what HP says the 49 prefix means.
- A malformed or unusual print job the firmware cannot process.
- A network or USB connection contributing to the fault.
- A surge protector between the printer and the wall.
- A firmware fault that needs service, if it returns every time.
What the 49 prefix means
HP displays these as 49.WX.YZ on the control panel of LaserJet Enterprise and PageWide Enterprise printers, and the leading 49 is the informative part: it indicates a firmware communication error. The digits after it narrow the specific failure, but the family meaning is constant.
HP’s own first line is that these errors are typically cleared by turning the printer off and then on. That is genuinely the recommended first step rather than a formality, and for an intermittent 49 it is often the whole answer.
The useful distinction is frequency. A 49 that appears once in a month and clears on a restart is a different thing from one that returns every time you print, and HP’s troubleshooting reflects that — the deeper steps are aimed at an error that persists.
Taking the connections out of the picture
For a persistent 49, HP’s steps are about isolating the printer. Turn it off and unplug the network and USB cables. If a surge protector is in use, remove it and plug the product directly into the wall socket. Then turn the printer on and see whether it reaches the Ready state.
That sequence answers a specific question: can the printer come up healthy on its own, with nothing sending it anything? A printer that reaches Ready with the cables out, and fails once they are back, points at what is being sent rather than at the printer.
The surge protector instruction looks odd next to a firmware error and is worth following anyway — HP names it explicitly, and eliminating it costs nothing.
The event log, and when it is service
HP’s remaining diagnostic is to print an event log to verify how often the error occurs. That turns an impression into a number, which matters because people report 49 errors as constant when the log shows three in a fortnight, and as occasional when the log shows dozens.
It also gives support something to work with. A 49 error with an event log behind it is a far more productive conversation than one described from memory.
HP’s endpoint is unambiguous: if the printer does not return to the Ready state, it requires service. At that point there is nothing further to try at the panel, and continuing to power cycle only delays the call.
Sources and review notes
Checked on . Based on HP’s support documentation for 49.XXXX errors on LaserJet and PageWide printers. The meaning of the 49 prefix, the isolation steps, the surge protector instruction and the event log are HP’s. The distinction drawn between an intermittent and a constant 49 is editorial. HP’s support pages render only in a browser and are not reliably fetchable. Glitchary is independent of HP.