"Receipt Printer Unavailable" Error Fix

Fix the POS “Receipt Printer Unavail.” error. Restore printer communication by rebooting, matching COM port settings, and reseating the RS-232 serial cable.

Use this when the POS shows “Receipt Printer Unavail.”

Use this when receipts won’t print and the register shows Receipt Printer Unavail.

This usually means the register can’t talk to the printer. The common causes are a reboot glitch, a COM port mismatch, or a loose RS-232 serial cable.

Stop rule

After each step, check the top of the POS screen.

If Receipt Printer Unavail. is gone, stop and print a receipt.

Also called / keywords

Also called: Receipt printer offline, POS printer error, register won’t print, printer not printing, receipt printer unavailable

Keywords: receipt printer offline, printer unavailable, POS printer error, register won’t print receipts, printer not responding, COM port error, RS-232, serial printer

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Symptoms

Receipt printer unavailable error on POS

You may see one or more of the following:

• “Receipt Printer Unavail.” at the top of the screen
• Receipts don’t print
• Printer looks powered on but prints nothing

Most often this means: The POS can’t communicate with the printer over the serial (COM) port.

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Not your issue?

• Printer has no lights → Receipt Printer No Power - Power LED Is Off
• Printer has a red error light → Receipt Printer Red Error Light Is On
• Receipts print gibberish → Receipt Printer Printing Gibberish or Random Characters
• Reprints work, but new sales don’t print → New Receipts Not Printing - Reprints Work But New Sales Receipts Don't

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Before you start (quick checks)

• Is the printer’s power light on?
• Is the printer connected by RS-232 serial (not USB/Ethernet)?
• Were any cables moved, swapped, or cleaned today?
• Is there a red error light on the printer? Fix that first: Receipt Printer Red Error Light Is On

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How to fix the "Receipt Printer Unavail." error

1

Reboot the register

Reboot the register fully and wait until it reaches the normal sales screen.

✅ Error gone and receipt prints? No further steps needed.

❌ Error still showing? Continue to Step 2.

2

Find the printer's assigned COM port number

On the register go to: Device Control → Managed Modules → System Resources

Or if using Config Client: Tools → Managed Modules → System Resources

Find the receipt printer and write down the port number shown. Example: COM1 or COM3.

3

Make sure the cable is plugged into the right port

Look at the back of the register. Find the port with the same number from Step 2. Check that the printer cable is plugged into that exact port.

✅ Cable is in the correct port → Continue to Step 4

❌ Cable is in the wrong port → Move it to the correct port, restart the register, and check if the error is gone. If resolved, stop here. If not, continue to Step 4.

4

Unplug and firmly plug back the cable

Unplug the printer cable from the back of the register and from the back of the printer. Plug both ends back in firmly until secure. Restart the register and check if the error is gone.

✅ Error gone? Issue is resolve, test the printer.

❌ Still showing? Continue to Step 5.

5

Try another COM port(COM port swap)

If the error is still there, try plugging the printer cable in a different available COM port on the back of the register.

Update the printer setting to match the new port under Device Control or on Tools → Managed Modules → System Resources.

Then, Reboot the register and test again.

6

Error message still there and receipts don't print?

• No on-site contract: Contact a VASC(Verifone Authorized Service Contractor)Technician for further on-site troubleshooting
• Valid on-site/contract: Contact the Verifone Helpdesk:

📞 Phone: [phone] (1-800-VERIFONE)

💬 Chat

Tell them exactly the troubleshooting steps performed, this saves your time and gets you the right support faster.

Advanced: run a diagnostic print test

1. Flip the #1 dip switch on the register down and reboot the register to enter into diagnostic mode.
2. Go to Peripherals > Printer > (tap the COM port the printer is connected to).
3. Tap 5x to print 5 lines of "a".
4. If nothing prints during this test, contact Verifone support.

To exit diagnostic mode, flip the #1 dip switch back up. Then press Exit until the POS reboots to normal mode.

Need assistance? Contact Verifone Helpdesk at anytime.

• Use our Chat platform
• Or call 1.800.VERIFONE (837.4366)

Tell us the troubleshooting steps you’ve already tried. This saves time and gets you the right support faster.