79
HP Printer
Severity: CriticalWhat Does This Error Mean?
The 79 error is a service error on HP LaserJet printers. It is similar to a 'blue screen' crash on a Windows computer. The printer's internal system encountered a critical failure and needs to be reset.
Affected Models
- HP LaserJet Pro M400 Series
- HP LaserJet Enterprise M600 Series
- HP LaserJet Pro MFP M428
- HP LaserJet Pro M200 Series
- HP Color LaserJet Enterprise M553
Common Causes
- A corrupted print job crashed the printer's internal processor
- The printer firmware is outdated or became corrupted during an update
- A network-connected device is sending malformed data to the printer
- The printer's formatter board (main circuit board) is failing
- Third-party firmware or unauthorized modifications are causing instability
How to Fix It
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Turn off the printer. Disconnect the network cable or USB cable to isolate the printer.
This prevents any connected computers from resending the problematic print job.
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On every computer that uses this printer, open the print queue and delete all pending jobs.
If the printer is on a network, check all computers that may have sent jobs to it.
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With the cables still disconnected, turn the printer back on and wait for it to fully start up.
If the error is gone at this point, the problem was a bad print job. Reconnect and try printing again.
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If the error returns even with cables disconnected, perform a factory reset. Check your printer manual for the specific button combination.
A factory reset erases all custom settings, so note down your network and preference settings first.
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Download and install the latest firmware from HP's support website. Use a USB connection for the most reliable firmware update.
Do not turn off the printer or disconnect it during a firmware update — this can make the problem worse.
When to Call a Professional
If the 79 error keeps appearing after clearing all print jobs, updating firmware, and power cycling, the formatter board may need replacement. A new formatter board typically costs $100 to $300 depending on the model. HP or an authorized service provider can install it.
Frequently Asked Questions
What is a formatter board?
The formatter board is the printer's main circuit board — think of it as the printer's brain. It processes print jobs, manages network connections, and controls all printer functions. When it fails, the printer experiences critical errors like the 79 error.
Is the 79 error different from the 49 error?
They are related but not identical. The 49 error is a firmware-level crash, while the 79 error is a deeper service-level failure. Both are often caused by corrupted print jobs. The 79 error is generally more serious and may indicate hardware issues.
Can I still use my printer after a 79 error?
If the error clears after a power cycle, yes — your printer is fine to use. But if the error keeps coming back, continued use may not be possible. Repeating 79 errors usually mean the formatter board or firmware needs attention.