HP Printer Error Code 40 — What It Means & How to Fix It

What Does This Error Mean?

Error 40 means there was a problem with the data being sent from your computer to the printer. The connection was interrupted or corrupted during transmission. Restarting both the printer and computer, then resending the job, usually fixes this.

Affected Models

HP LaserJet 4
HP LaserJet 4 Plus
HP LaserJet 5
HP LaserJet 4050
HP LaserJet 8000

Common Causes

The USB or parallel cable between the computer and printer became loose or disconnected during printing
The cable itself is faulty or too long, causing signal degradation
A network interruption occurred while sending a print job over Wi-Fi or ethernet
The print driver sent corrupted data due to a software glitch
The computer went to sleep or hibernated partway through transmitting the print job

How to Fix It

Press the Continue or Go button to clear the error. The current print job will be cancelled.

Do not try to resend the job yet. Clear the queue completely first.
Turn off both the printer and your computer. Wait 30 seconds, then turn them both back on.

A full restart clears any corrupted data stuck in the communication buffer on both devices.
Check the cable connecting the printer to the computer. Make sure it is firmly plugged in at both ends.

If using a USB cable, try unplugging and replugging it. Try a different USB port on your computer if available.
If you are using a parallel cable (older printers), consider replacing it with a shorter, higher-quality cable.

Parallel cables over 6 feet (2 meters) can suffer signal loss that causes error 40.
Resend the print job. If the error returns, try printing a different, simpler document first to confirm the connection is working.

If a simple document prints fine but the original document fails, the document itself may be corrupted. Try recreating or re-exporting it.

When to Call a Professional

Error 40 is almost always a connection or software issue, not a hardware failure. If the error persists after replacing the cable and updating the driver, a technician can run deeper diagnostics. For persistent network printing issues, your IT professional can check network configuration. Contact HP Support at 1-800-474-6836 for driver and connectivity assistance.

Frequently Asked Questions

Does error 40 mean my printer is broken?

No. Error 40 is almost always a communication problem between the computer and printer. It is not a sign that the printer's internal hardware is damaged. Fixing the cable or restarting both devices usually resolves it completely.

Can a wireless connection cause error 40?

Yes. Wi-Fi dropouts or network congestion can interrupt data transmission and trigger error 40. Try printing with a USB cable instead to see if the wireless network is the problem. If USB printing works fine, the issue is with your wireless connection or router.

Why does error 40 keep coming back?

A recurring error 40 usually points to a damaged cable, a faulty USB port, or an unstable network connection. Try a different cable first — they are inexpensive and often the culprit. Also make sure your printer driver is up to date by checking HP's website.