Attention required HP

HP Error 49.4C02

What the code means · Diagnosis at a glance

HP error 49.4C02 (part of the 49.x service-error family, also shown as “49 Service Error”) is a firmware fault on HP LaserJet printers. It is almost always triggered by a corrupt or malformed print job (a bad PDF, PostScript or PCL data stream) that the printer’s formatter cannot process, forcing the firmware to halt. Outdated firmware and driver/language mismatches are the other common triggers; a failing formatter board or onboard network module is a rarer cause. In most cases you can clear it yourself by power-cycling, disconnecting the cable and clearing the print queue.

Jump to the fix ↓ HP official support ↗
Safe to tryPower-cycling, disconnecting the cable and clearing the print queue are all safe, non-invasive steps.
Do not open internal partsIf you run a firmware update, do not power off or disconnect the printer mid-update: an interrupted update can corrupt the firmware.
May need a technicianIf the error survives a cable disconnect, a cleared queue and a firmware reflash, the formatter or network hardware may be failing and needs a technician.
Model-specificThe exact firmware file and driver depend on your specific LaserJet model, so always download them for your exact model number.

Affected brands & models

HP LaserJet M140weHP LaserJet P1102HP LaserJet Pro seriesHP LaserJet MFP series

Diagnosis at a glance

Likely causes ranked, with severity and the recommended action.

Corrupt or malformed print job (bad PDF/PostScript/PCL) Attention Likelihood: Most likelyAction: Disconnect the cable, clear the queue, fix the file before resending
Outdated or buggy firmware Attention Likelihood: CommonAction: Update the firmware; roll back if it started after an update
Driver / page-language mismatch Quick fix Likelihood: OccasionalAction: Switch to the HP Universal PCL6 driver

What the code means

A 49 error is the printer telling you its formatter (the small onboard computer that turns your document into printable data) hit something it could not process and shut down to protect itself. The most frequent trigger is a single bad print job: a PDF, PostScript or PCL data stream that is corrupt or malformed. The printer reaches that job in the queue, chokes on it, and displays 49.4C02. Because the job is stored, simply turning the printer off and on can bring the same job straight back and re-trigger the error.

The other common triggers are firmware and drivers rather than a physical fault. Outdated or buggy firmware can mishandle certain jobs, and a driver or page-language mismatch (for example sending a PostScript stream to a printer set up for PCL, or the reverse) can produce data the formatter rejects. Only more rarely is the cause hardware: a failing formatter board or the onboard network (LAN) module. That order matters, because it means the first things to try are free and non-invasive.

Most frequent causes

  • A corrupt or malformed print job (bad PDF, PostScript or PCL data) that the formatter cannot process.
  • Outdated or buggy printer firmware.
  • A driver or page-language mismatch between the computer and the printer (PostScript sent to a PCL setup, or the reverse).
  • More rarely, a failing formatter board or onboard network (LAN) module.

Quick fix: try this first

  1. Turn the printer off, wait about 30 seconds, and turn it back on.
  2. Disconnect the network or USB cable and power on. If it reaches “Ready” with the cable off, a bad print job is the cause.
  3. Clear the print queue and cancel every stuck job on all computers that print to it.

Step-by-step solution

0 / 6 done

Tick each step as you go. Your progress is kept while you work.

Before you start

  • Note the full error text and your exact model number.
  • Make sure you can reach every computer that sends jobs to this printer.
  • Have the printer’s model-specific firmware and driver download page ready (from HP support).

What not to do

  • ×Don’t keep re-sending the same document that triggered the error. It will just halt again.
  • ×Don’t ignore pending firmware updates; an old firmware version is a common cause.
  • ×Don’t assume it is always a hardware failure: on 49.x it is usually the print job.

When to stop & call support

Stop and arrange HP service if 49.4C02 returns immediately even with the network and USB cables disconnected and the print queue cleared, and it still persists after you have updated (or rolled back) the firmware. At that point the likely cause is no longer a bad job but the formatter board or onboard network module, which are service parts rather than user repairs.

If the error comes back

If the error clears but comes back the next time you print, focus on the source of the job rather than the printer. Identify which computer and which document reproduce it, remove or re-create that file, confirm the driver matches the printer’s page language, and keep the firmware current. A 49.x that only appears with one specific file or one specific computer is a data problem, not a failing printer.

Related parts & consumables

Formatter boardService part: rare cause, replaced by a technician
Onboard network (LAN) moduleService part: rare cause, replaced by a technician

Questions about HP 49.4C02

Does 49.4C02 mean my printer is broken?

Usually not. The 49.x family is a firmware halt, and it is most often caused by a single corrupt print job rather than failed hardware. Clearing the queue and power-cycling fixes the majority of cases.

Why does the error come back as soon as I turn the printer on?

The bad job is stored in the queue, so the printer reaches it again right after restarting. Disconnect the cable and clear the queue on every computer before powering back on.

The error started right after a firmware update: what now?

Roll back to the previous stable firmware for your model. A buggy or mismatched firmware build can trigger 49.x, and reverting it often resolves the error.

PrinterErrors editorial team

Last updated · Content is independent and not sponsored by any manufacturer.

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