HP Printer Error Code 49.4 — What It Means & How to Fix It

What Does This Error Mean?

The HP printer error 49.4 (also displayed as 49.4C02, 49.4C06, or similar) is a firmware error. It means the printer's formatter board received a print job or data packet it could not process — and halted to prevent further problems. This is one of the most common critical errors on HP LaserJet printers. The most frequent cause is a corrupted print job. In many cases, simply clearing the print queue and restarting the printer fixes it completely.

Affected Models

HP LaserJet Pro M402
HP LaserJet Pro M404
HP LaserJet Pro MFP M428
HP LaserJet Enterprise M607
HP Color LaserJet Pro M454
HP LaserJet Pro M501

Common Causes

A corrupted or overly complex print job — the most common cause by far
An outdated printer firmware version with a known processing bug
An incompatible or outdated printer driver installed on the sending computer
Network communication error that garbled the print data during transmission
Failing formatter board inside the printer that can no longer process jobs reliably

How to Fix It

Turn off the printer using the power button and disconnect the USB or network cable. Wait 30 seconds. This prevents the corrupted job from being automatically resent when the printer restarts.

Do not skip disconnecting the cable. If the printer reconnects to the network or computer while restarting, the bad job can be sent again immediately.
On your computer, clear the print queue completely. In Windows, go to Settings > Bluetooth and devices > Printers and scanners, click your printer, then open the print queue and cancel all pending jobs.

Sometimes a job stays stuck in the queue even after you think you have deleted it. Restart the Windows Print Spooler service if jobs will not clear: open Services, find 'Print Spooler', right-click, and select Restart.
Turn the printer back on and wait for it to finish starting up. Once it shows 'Ready', reconnect the cable. Try printing a simple test page from the printer's own menu — not from your computer.

If the printer's own test page prints without error, the problem was in the print job or driver. If the error reappears during startup, the firmware or formatter board is suspect.
Update the printer firmware. Visit support.hp.com, search for your printer model, and download the latest firmware update. Install it according to HP's instructions.

Firmware updates often fix known 49.4 error triggers. Always update firmware before replacing hardware.
Uninstall and reinstall the printer driver on your computer. Download the latest driver directly from support.hp.com — do not use the driver CD that came with the printer, as it may be outdated.

When reinstalling, choose a fresh installation rather than an upgrade. This ensures no corrupted driver files carry over from the old installation.

When to Call a Professional

If 49.4 keeps returning after clearing the queue, updating firmware, and reinstalling the driver, the formatter board may be failing. Formatter board replacement costs $80 to $250 depending on the LaserJet model. An HP-certified service center can confirm whether the board is the cause before you spend money on parts.

Frequently Asked Questions

What does the extra code after 49.4 mean — like 49.4C02 or 49.4C06?

The letters and numbers after the dot and letter are sub-codes that HP technicians use to narrow down which part of the firmware failed. For most users, they do not change the troubleshooting steps. If you need warranty service or depot repair, share the full code (including the sub-code) with HP support.

Can a PDF cause a 49.4 error?

Yes — PDF files with embedded fonts, transparency effects, or very high-resolution images are common triggers for 49.4 errors. If printing a PDF triggers the error, try printing it as an image instead. In Adobe Reader: File > Print > Advanced > 'Print as Image'.

Does 49.4 mean my printer is broken?

Not necessarily. The vast majority of 49.4 errors are caused by the print job, not the printer hardware. Try clearing the queue, updating firmware, and reinstalling the driver first. Only suspect the formatter board if the error persists across multiple different computers and print jobs.