Receipt prints gibberish / random characters

Fix unreadable receipts by matching the COM port and baud rate (usually 38400).

Use this when receipts print gibberish or random characters

Use this when receipts print symbols or unreadable text.

This is usually a COM port or baud rate mismatch between the POS and printer.

Stop rule

After each step, print a test receipt.

If it prints normally, stop.

Also called / keywords

Also called: Printer printing symbols, gibberish on receipt, printer printing garbage, unreadable receipt text, corrupted receipt printing

Keywords: receipt printing gibberish, random characters on receipt, printer symbols instead of text, garbled receipt, baud rate mismatch, COM port wrong, RP330 baud rate, TM-88 gibberish, RP300 gibberish, RP310 gibberish

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Symptoms

You may see one or more of the following:

• Receipts print random symbols or unreadable text.
• Paper feeds normally, but the text is wrong.
• The printer self-test prints clearly, but POS receipts are gibberish.

Gibberish /random characters printed from printer

Most often this means: The POS and printer settings don’t match. Check COM port first, then baud rate.

Not your issue?

• POS shows Receipt Printer Unavail. → “Receipt Printer Unavailable” Error Fix
• Reprints work, but new sales don’t print → New receipts not printing (reprints work)

Before you start (quick checks)

• Is it gibberish on every receipt?
• Were any cables moved or replaced today?
• Printer model: TM-88, RP300, RP310, or RP330

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How to fix receipts printing gibberish / random characters

1

Confirm the printer COM port assignment

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

Or via Config Client: Tools → Managed Modules → System Resources

Find the receipt printer entry and note the COM port number shown. Example: COM1 or COM3.

2

Match the cable to that COM port, then reboot

Look at the back of the register.

Make sure the printer cable is plugged into the same COM port you found in Step 1.

• If it’s in the wrong port, move it to the correct COM port.
• Reboot the register.
• Print a test receipt.

If it still prints gibberish, go to the Step 3.

3

Check and set the printer baud rate (target: 38400)

If the COM port is correct and it still prints gibberish, match the printer’s baud rate.

TM-88 / RP300 / RP310 (dip switches)

These models use internal dip switches.

1. Power off the printer.
2. Open the cover to find the dip switch panel.

Dip switches after opening the panel

1. Match your switches to the standard settings below.

Standard Dip switch positions for TM-88 model printer

Standard Dip switch positions for RP-300/RP-310 model printers

1. Close the cover, power on, and print a test receipt.

RP330

RP330 baud rate is set from the printer’s button menu.

Verify baud rate

1. Paper loaded.
2. Power off.
3. Hold FEED and power on.
4. On the self-test print, confirm baud rate is 38400.

Change baud rate (if not 38400)

1. Power off.
2. Hold FEED and power on.
3. On the printout, find SELECT MODE BY BUTTON.
4. Press FEED twice to select BAUDRATE MODE.
5. Press FEED until 38400 is selected.
6. Wait for the confirmation print, then power cycle.
7. Print a POS test receipt.

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Still printing gibberish?

• 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)

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

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