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# My Star Micronics printer prints unreadable characters

# **Unreadable printing issue: update the printer firmware**

If your receipt prints with **unreadable characters**, **random symbols**, or corrupted content, this is **in most cases caused by a printer firmware issue**, especially when using a **Bluetooth** connection.

This issue often occurs after:
* an operating system update (iOS / Android),
* switching to a different POS application,
* or the initial setup of the printer.

The solution is to **update the printer firmware**.

![Printing issue](https://storage.crisp.chat/users/helpdesk/website/-/1/1/5/8/11586f3f280f9f00/image_5x14w2.png =343xauto)

---

## **Step 1 — Update the printer firmware**

[Star Micronics](chatgpt://generic-entity?number=0) provides an official application to configure and update its printers.

### **1. Download the official Star Micronics app**
* **Android**: https://play.google.com/store/apps/details?id=com.starmicronics.starquicksetuputility  
* **iOS (iPhone / iPad)**: https://apps.apple.com/app/id1549088652

### **2. Connect the printer in the app**
1. Turn on the printer.  
2. Enable **Bluetooth** on your phone or tablet.  
3. Open the **Star Quick Setup Utility** app.  
4. Select your printer from the list of detected devices.

---

## **Step 2 — Run the firmware update**

### **1. Access the update menu**
In the app, follow this path:

**Printer Settings**

![](https://storage.crisp.chat/users/helpdesk/website/-/1/1/5/8/11586f3f280f9f00/capture-decran-2026-01-12-a-18_yebtsu.png =343x703)

Firmware update:

![](https://storage.crisp.chat/users/helpdesk/website/-/1/1/5/8/11586f3f280f9f00/capture-decran-2026-01-12-a-18_1ju5w25.png =343x710)

### **2. Update the firmware**
1. Tap **Firmware Update**.  
2. If an update is available, start it.  
3. **Do not turn off the printer** and **do not close the app** during the update.  
4. Wait for the confirmation that the update is complete.

Once the update is finished:
* restart the printer,
* open the **Tunder** app,
* **remove the printer and add it again**,
* then run a test print.

---

## **Step 3 — If the issue persists: perform a factory reset**

If the receipt is still unreadable after updating the firmware, you need to perform a **full factory reset** of the printer.

### **1. Why perform a factory reset?**
* removes old Bluetooth settings,
* resets internal configuration,
* resolves persistent software conflicts.

### **2. Reset procedure (general principle)**
> ⚠️ The exact procedure may vary depending on the printer model.

1. Turn off the printer.  
2. Press and hold the **power button**.  
3. Turn the printer back on while holding the button.  
4. Release the button when the LEDs start flashing or when a configuration receipt is printed.

After the reset:
* reconnect the printer via Bluetooth,
* reconfigure it in the **Tunder** app,
* run a new test print.