Star printer prints garbled receipts (switch to ESC/POS)

The problem

Your Star printer (for example the mC-Print3, or a TSP143) prints something, but it comes out wrong:

• Big blank gaps running down the receipt, with the text spread out over a long strip of paper.
• Stray single characters — like !, . or " — printed at the start of lines where they don't belong.
• Tiny, plain text with none of the usual bold headings, larger order number, or neat alignment.

The paper feeds and the printer cuts, so the hardware is healthy. The receipt just looks like scrambled fragments instead of a proper ticket.

Why it happens

Receipt printers understand a "command language" — the invisible instructions that tell the printer to make text bold, change size, line things up, and cut the paper. The POS speaks a language called ESC/POS.

Star printers are dual-language, but they come out of the box set to Star's own language, StarPRNT. When the POS sends ESC/POS instructions to a printer that's still listening for StarPRNT, the printer doesn't recognise the commands — so it prints the formatting instructions as stray characters (the stray ! and . you see) and mishandles the spacing (the big gaps).

The fix is a one-time setting on the printer: switch it from StarPRNT to ESC/POS. Nothing needs to change in the POS.

Note: This is a printer setting, not a fault. Once you switch it, it stays switched — it survives being turned off and on.

Which printers this applies to

Any Star Micronics receipt printer that defaults to StarPRNT emulation, including:

• mC-Print3 (model MCP30) and mC-Print2
• TSP143 / TSP654 and other TSP-series models

If your receipt printer is a Star model and receipts look garbled as described above, this is almost certainly the cause.

Fix — Option A: Star Quick Setup Utility app (easiest)

Star's free phone app can change the setting over your network.

1. On a phone or tablet on the same Wi-Fi network as the printer, install Star Quick Setup Utility from the App Store (iOS) or Google Play (Android).
2. Open the app and let it find your printer, then select it from the list.
3. Go to Printer Settings (you may need to tap into the detailed or Memory Switch settings).
4. Find Emulation and change it from StarPRNT to ESC/POS.
5. Apply / Save. The printer restarts to take on the new setting.

Then jump to Check it worked below.

Fix — Option B: the printer's web page

Use this if the printer is on Ethernet or Wi-Fi and you'd rather not install the app.

1. Find the printer's address and current setting. With the printer switched off, hold down the FEED button and switch it back on — keep holding until it prints a self-test / settings sheet. This sheet shows the printer's IP address and its current Emulation (it will say StarPRNT, confirming the problem).
2. On a computer or phone on the same network, open a web browser and go to http://<printer-ip> (use the IP address from the sheet).
3. Log in if asked. The Star default is username root, password public.
4. Find the Emulation or Memory Switch setting and change it to ESC/POS.
5. Save / Apply. The printer restarts.

Check it worked

1. Print the self-test sheet again — hold FEED while switching the printer on. The Emulation line should now read ESC/POS.
2. In the POS, go to Settings > Select Printers, pick the Star printer as your Customer Printer, and tap Test Print (or reprint a recent order).
3. The receipt should now come out correctly: proper alignment, bold headings, the larger order number, no stray symbols, and a clean cut.

Note: If receipts are still garbled after switching to ESC/POS, double-check you saved the setting and that the printer restarted — reprint the self-test sheet to confirm the Emulation line changed.

Related

• Set up printers
• Find and assign network printers with Discover