1) Printer Overview & Connections

Before you begin, familiarize yourself with the key parts of your KL-787 printer, as referenced in the setup steps below.

• (1) Feed Button – Advances paper, runs tests, and changes modes.
• (2) Paper Outlet – Output for labels/receipts.
• (3) Status Light – Indicates printer status (ready, error, etc.). See next section for details.
• (4) Opening Button – Press this to open the top cover and access the paper compartment.
• (5) LAN Port (optional) – For connecting to a network router.
• (7) Cash Drawer – RJ11 cash box interface to trigger a cash drawer.
• (8) USB – Standard connection for a PC or POS system.
• (9) Power Switch – Turns the printer on/off.

Tip: Use a stable power source and always use the original adapter (DC 24V–1.5A) for consistent print density and to protect the hardware.

What’s in the Box? (Packing List)

Your new printer package includes everything you need to get started:

• Printer (×1)
• Power Adapter (×1)
• USB Cable (×1)
• User Guide (×1)
• Label paper (×1 starter roll)
• LAN cable (×1, optional, included with LAN models)

2) Understanding the Status Light

The Status Light (3) provides instant feedback on the printer’s condition. Here is a quick guide to what the different colors mean:

Blue Light

• Solid Blue: Bluetooth connection is active and successful. (For Bluetooth models only).
• Flashing Blue: The printer is in Bluetooth pairing mode and is discoverable, but not yet connected.

Red Light

• Solid Red: The top cover is open. Close the cover firmly until it clicks to resume.
• Flashing Red (Slowly): The printer is out of paper. Load a new roll to continue.
• Flashing Red (Quickly): The printer’s thermal head is overheating. Stop printing and allow the printer to cool down for several minutes. This is an automatic safety feature.

3) Load Receipt or Label Paper (40–80mm)

Loading paper correctly is the most important step to prevent jams and blank prints. The KL-787’s auto-correction feature makes this simple.

1. Press the Opening Button to open the cover.
2. Place the roll (58mm or 80mm receipt paper, or adhesive label roll) in the compartment.
3. Face the thermal side up (toward the print head).
4. Pull a short lead past the Paper Outlet and close the cover firmly.
5. The printer will auto‑correct and feed to the next label start.

4) Install Kolon KL‑787 on Windows 10/11

Follow these steps to connect your printer to a Windows-based PC or POS terminal.

1. Download and install the Windows driver.
2. Connect via USB (or LAN if your model supports it).
3. Open Printers & Scanners → Add device → select KL‑787.
4. Open Printer Preferences → set paper size (58mm or 80mm) & media type (receipt or label).
5. Print a test page to verify connection and density.

If you get blank prints: the roll is upside down. Re‑load with thermal side up.

5) Print from Android / iOS (Mobile App)

For Bluetooth-enabled models, you can print directly from your phone or tablet using the MHT Cloud application.

1. Install the MHT Cloud app.
2. Power on the printer and enable Bluetooth (if your model supports BT).
3. In the app, add printer: select KL‑787 and pair.
4. Choose Label or Receipt template; set width (40–80mm).
5. Send a test print from the app to confirm connection.

6) Advanced Operations & Button Functions

The Feed Button (1) is used for more than just advancing paper. By holding it while turning on the Power Switch (9), you can access several key configuration modes. Listen for the buzzer.

• Print Self‑Test:With the printer off, hold Feed, then turn power on. Release the Feed button immediately after hearing the first beep. This will print a test page showing all current settings, including firmware version and IP address (if on LAN).
• Switch Mode (Label ↔ Receipt):This is essential when changing paper types. With the printer off, hold Feed and turn power on. Keep holding past the first beep. Release the button after hearing the second beep. The printer will toggle its media mode.
• Factory Reset:To restore all settings to their original defaults, hold Feed and turn power on. Keep holding past the first, second, and third beeps. Release the button after hearing the fourth beep.
• Calibrate Labels (Paper Correction):If your labels are not aligning to the gap, you can force a calibration. With the printer on and ready, simply long-press the Feed button until you hear a single beep, then release. The printer will feed the paper and re-detect the label gaps.
• Increase Print Concentration (Darkness):If your prints are too light, you can make them darker. With the printer on and ready, quickly press the Feed button two (2) times. The printer has 8 concentration levels, and this will increase the darkness by one level.
• Reduce Print Concentration (Lightness):If your prints are too dark or “bleeding” (especially on cheap paper), you can make them lighter. With the printer on and ready, quickly press the Feed button four (4) times. This will decrease the darkness by one level.
• Pause / Resume Printing:During a long print job, you can pause it by quickly clicking the Feed button once. To resume the print job from where it left off, quickly click the Feed button once again.

7) Network Setup: Using the LAN Port (DHCP)

For LAN-enabled models, the printer defaults to an active DHCP setting, meaning it will try to get an IP address from your router automatically. After it successfully gets an IP, it switches to a static IP to maintain a stable connection.

If you change your network or router, you may need to re-activate DHCP to get a new IP address. Printing a self-test page (see section 6) will show you the current IP address.

How to Manually Re-activate DHCP

1. Turn the printer on and make sure paper is loaded.
2. Press the Opening Button (4) to open the top cover.
3. With the cover open, press and hold the Feed button (1).
4. Keep holding the button for about 5-6 seconds, until you hear the buzzer ring 3 times.
5. Release the button. DHCP is now activated.
6. Close the cover and print a new self-test page to find the new IP address assigned by your router.

Troubleshooting Your KL‑787

Detailed Precautions & Safe Operation

To ensure the long life and reliable operation of your printer, please follow these maintenance and safety precautions from the official user guide. Failure to do so can damage the print head, roller, or control circuits.

Environmental Precautions

• The printer should be installed in a flat, stable, and level place.
• Leave enough space around the printer for easy operation and maintenance access.
• Keep the printer far away from water sources. Do not operate in areas of high humidity, and avoid any condensation (damp air) from forming on the surface. If dew has formed, do not turn on the power until it has completely disappeared.
• Avoid direct sunlight, strong light, and direct heat sources (like heaters or radiators).
• Do not use or store the printer in places with high temperature, high humidity, or serious pollution (e.g., dusty workshops).
• Avoid placing the printer in locations subject to vibration and shock.

Electrical Safety

• Always turn the power off before performing daily maintenance or cleaning.
• Connect the power adapter to an appropriate, properly grounded socket.
• Avoid using the same socket as large motors or other equipment that can cause power voltage fluctuations, as this can lead to unstable printing.
• If you do not use the printer for a long time, please disconnect the power adapter from the outlet.
• When connecting or disconnecting any interface cable (like USB or LAN), the printer power must be turned off first to avoid damaging the printer’s control circuit.
• Prevent water or conductive substances (e.g., metal paper clips, staples, spills) from entering the inside of the printer. If this occurs, the power should be turned off immediately.

Operational Guidelines

• Never print without paper. The printer shall not be operated without paper loaded, as this will seriously damage the printer rubber roller and the thermal print head.
• Clean the Print Head: Over time, paper dust and adhesive can build up on the print head, causing blurry or faded prints. After every few rolls, gently wipe the thermal print head with a soft cloth and isopropyl alcohol (with the power off and head cooled down).
• Reduce Print Concentration: When the printing effect is clear and meets your requirements, it is recommended that users reduce the printing concentration (see section 6) as much as possible. Running at maximum darkness at all times can affect the service life of the print head.
• Users are not allowed to disassemble the printer for overhaul. Any unauthorized service will void the warranty.

Kolon KL‑787 Technical Specifications

FAQs: Using the Kolon KL‑787 Receipt Printer

Buy Kolon Printers in the Middle East

      For official sales and support in the Middle East, contact our trusted partner and printer supplier:

   
AtoZ Security Equipment

      Leading distributor for KolonPOS equipment (barcode & label printers) across the Middle East.