1. Introduction
The YILTION NF-859GK is a multi-functional network cable tester designed for comprehensive network diagnostics. It integrates various testing capabilities including Power over Ethernet (PoE) detection, IP/PING testing, Time Domain Reflectometry (TDR) for cable length measurement, port flicker location, continuity testing, and fiber optic continuity (VFL). This manual provides detailed instructions for the proper use and maintenance of your NF-859GK device.
2. Safety Information
- Read all instructions carefully before operating the device.
- Do not attempt to disassemble or modify the device. Refer all servicing to qualified personnel.
- Avoid exposing the device to extreme temperatures, humidity, or direct sunlight.
- Use only the specified charging cable and power adapter to prevent damage.
- Ensure proper connection of cables to avoid electrical hazards or damage to the device and connected equipment.
- When testing live circuits, exercise caution and follow standard electrical safety procedures.
3. Package Contents
Verify that all items are present in your package:
- NF-859GK Network Cable Tester (Main Unit)
- NF-859G Receiver
- USB-C Charging Cable
- RJ45 Cable
- RJ11 Cable
- Alligator Clip Cable
- Carry Bag
4. Product Overview
The NF-859GK consists of a main testing unit (Transmitter) and a remote receiver unit. Familiarize yourself with the components and controls of both units.

This image displays the main NF-859GK unit with its color screen and control buttons, alongside the slender receiver unit with its LED indicators and probing rod. Both units are black with red accents.

This diagram highlights the various ports and buttons on the main NF-859GK unit, including the big color screen, On/Off key, Confirm key, Up/Down keys, Return key, Type-C Charging Port, Telephone wire Detection port, Port Blinking/Length Test/Rate port, POE/PING/IP port, and Crimping/Alignment port.

This diagram illustrates the features of the NF-859G receiver, including the Probing Rod, Power Indicator, Wire Detection Signal Indicator, Wire Detection Sensitivity Adjustment Knob, On/Off Key, Wire Detection Key, Alignment Test Key, Flashlight Key, Red Light Key, Local Alignment Test R Port, PoE Test Port, Type-C Charging Port, Crimping Test Port, Local Alignment Test M Port, M Wiring Sequence Indicator, R Wiring Sequence Indicator, and Remote Alignment Test A Port (under bottom cover).
5. Setup
5.1 Initial Charging
Before first use, fully charge both the main unit and the receiver. Connect the provided USB-C charging cable to the Type-C charging port on each device and to a standard USB power adapter (not included). The charging indicator will show the charging status. A full charge typically takes approximately 2 hours and provides up to 10 hours of working time.

This image shows the main unit's screen displaying battery level and highlights the USB-C charging port, indicating a 1500mAh battery with 10 hours working time and 2 hours quick charge.
5.2 Powering On/Off
To power on the main unit or receiver, press and hold the On/Off key until the screen or indicators light up. To power off, press and hold the On/Off key again until the device shuts down.
6. Operating Instructions
The NF-859GK offers multiple testing functions accessible via the main unit's menu. Use the Up/Down keys to navigate and the OK key to select a function.

This image displays the main menu of the NF-859GK, showing icons for various functions such as Continuity, Scan, Port Flash, Length, POE, PING, IP Scan, Switch, and Set. It also highlights compatibility with CAT5/5e, CAT6/6a, CAT3, RJ45, and RJ11 cables.
6.1 Continuity Test (CONT)
This function checks the wiring sequence and continuity of RJ45 and RJ11 cables, identifying open circuits, short circuits, and cross-overs.
- Standard Test (Main Unit + Receiver):
- Connect one end of the cable to the RJ45/RJ11 port on the main unit.
- Connect the other end of the cable to the corresponding RJ45/RJ11 port on the receiver (labeled 'R' or 'Remote Alignment Test A Port' under the bottom cover).
- Select 'Cont' from the main menu. The screen will display the pin-to-pin mapping.
- Loopback Test (Main Unit Only):
- For short cables where both ends are accessible, connect one end to the main unit's RJ45/RJ11 port and the other end to the 'Local Alignment Test M Port' on the receiver (if using the receiver for loopback) or directly to the main unit's loopback port if available.
- The device will display the continuity results.
Note: For the long-distance continuity test, ensure the remote end is connected to the 'Remote Alignment Test A Port' on the receiver, which is typically found under a removable cover on the receiver's base. Using other 'CONT' ports for long-distance testing may result in incorrect readings (e.g., all pins shorted).

This image shows the NF-859GK main unit displaying continuity test results for RJ11 and RJ45 cables, indicating successful connections with green checkmarks for each pin. It also illustrates the QC Test function.

This image demonstrates various cable continuity test results (Good, Cable Cross, Short Circuit, Cable Open) and the QC function, showing how the NF-859GK identifies different wiring faults.
6.2 Scan Function (Wire Tracing)
The scan function helps locate and identify cables using either digital or analog toning.
- Connect the cable to be traced to the main unit's RJ45/RJ11 port.
- Select 'Scan' from the main menu. Choose between 'Digital Mode' or 'Analog Mode'.
- Use the receiver's probing rod to trace the cable. The receiver will emit an audible tone when near the cable. Adjust the sensitivity knob on the receiver for optimal detection.
Note: The digital scan mode generally offers better performance but may have a limited range, requiring the receiver to be in close proximity to the cable. The analog scan mode may produce a fainter signal with more static. The receiver's probe may be too thick to fit directly into an RJ45 jack; connect a short patch cable to the jack and then probe the patch cable.
6.3 Port Flash
This function helps locate a connected network port on a switch or router by causing its indicator light to flash.
- Connect the main unit to a network port on the switch/router using an RJ45 cable.
- Select 'Port Flash' from the main menu.
- Observe the indicator lights on the switch/router. The port connected to the NF-859GK will flash, allowing for easy identification.

This image shows the NF-859GK main unit connected to a network switch, with the screen indicating 'Port flash' and instructing the user to observe the indicator. The connected port on the switch is shown blinking.
6.4 Cable Length Measurement (TDR)
The TDR (Time Domain Reflectometry) function measures the length of network cables and identifies the location of faults like breaks or shorts.
- Connect one end of the cable to be measured to the main unit's RJ45 port.
- Ensure the other end of the cable is not connected to any device or the receiver. It must be an open circuit for accurate measurement.
- Select 'Length' from the main menu. The device will display the cable length in meters or feet.
Note: The minimum measurable length is approximately 4 meters. If the cable is shorter or if the remote end is connected, the device may display an error such as "Cable Open or beyond range." The accuracy may vary slightly, typically within a few feet.

This image illustrates the NF-859GK main unit displaying a cable length measurement of 200 meters, emphasizing its capability for QC functions and cable length measurement for various cable types.
6.5 POE (Power over Ethernet) Test
This function detects PoE voltage, polarity, and power supply type (IEEE 802.3af/at standard or non-standard).
- Connect the main unit to a PoE-enabled port on a switch or injector using an RJ45 cable.
- Select 'POE' from the main menu.
- The screen will display the PoE voltage, pin configuration, and standard (e.g., IEEE 802.3af, 802.3at).

This image shows the NF-859GK main unit displaying POE test results, indicating support for both 802.3af and 802.3at standards, along with voltage readings for each pin.
6.6 PING Test
The PING test verifies network connectivity and measures response times to an IP address or server.
- Connect the main unit to an active network port using an RJ45 cable.
- Select 'PING' from the main menu.
- Enter the target IP address. Use the Up/Down keys to navigate between number segments and the OK key to change the selected number. The Back key confirms the entry.
- Initiate the PING test. The screen will display statistics including success rate, minimum/maximum/average response times, and packet loss.
Note: The interface for entering IP addresses can be unintuitive. Pay attention to the on-screen highlighting to ensure correct input. The 'Conut' field refers to the number of PING attempts.

This image shows the NF-859GK's interface for performing PING tests and setting IP addresses, displaying successful PING statistics and options to save or exit.

This image displays the NF-859GK showing PING test results and network rate test results, indicating the detected speed (e.g., 1000Mbps) and duplex mode (Full Duplex).
6.7 IP Scan
The IP Scan function scans a specified IP range to discover active devices and their IP addresses on the network.
- Connect the main unit to an active network port using an RJ45 cable.
- Select 'IP Scan' from the main menu.
- Enter the starting and ending IP addresses for the scan range.
- Initiate the scan. The device will list discovered IP addresses.
Note: Similar to PING, the IP input interface requires careful navigation.

This image shows the NF-859GK's IP Scan interface, displaying the start and end IP addresses for a scan, and a list of detected IP addresses.
6.8 Switch Test (Network Rate Test)
This function reports the link speed and duplex mode of the connected network port.
- Connect the main unit to a network port on a switch or router using an RJ45 cable.
- Select 'Switch' from the main menu.
- The device will display the detected link speed (e.g., 10M/100M/1000M) and duplex mode (Full Duplex/Half Duplex).
Note: This function reports the configured speed of the switch port, not necessarily the actual throughput or link speed under load.
6.9 Fiber Optic Continuity (VFL)
The Visual Fault Locator (VFL) function helps identify breaks or bends in fiber optic cables by emitting a visible red laser light.
- Connect the fiber optic cable to the VFL port on the receiver unit.
- Activate the VFL function (usually via a dedicated button or menu option on the receiver).
- Observe the fiber cable. Red light escaping from the cable indicates a break or severe bend.
Note: An appropriate fiber optic connector adapter (e.g., FC, SC, ST, LC) may be required and is typically not included. The effectiveness of VFL can vary on very long fiber runs.

This image shows the NF-859G receiver unit with a fiber optic cable connected, illustrating the VEL (Visual Fault Locator) function for fast fiber finding and power detecting range.
7. Maintenance
7.1 Cleaning
Wipe the device with a soft, dry cloth. Do not use abrasive cleaners or solvents. Keep the ports free of dust and debris.
7.2 Battery Care
The device uses a built-in 1500mAh 3.7V lithium battery. To prolong battery life:
- Charge the device regularly, even if not in use for extended periods.
- Avoid fully discharging the battery frequently.
- Store the device in a cool, dry place when not in use.
7.3 Storage
When not in use, store the NF-859GK and its accessories in the provided carry bag to protect them from dust and physical damage.
8. Troubleshooting
If you encounter issues with your NF-859GK, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| Device does not power on. | Low battery; device fault. | Charge the device fully. If issue persists, contact support. |
| Continuity test shows incorrect results (e.g., all pins shorted). | Incorrect port used on receiver for long-distance test. | Ensure the remote end of the cable is connected to the 'Remote Alignment Test A Port' on the receiver. |
| Cable length test displays "Cable Open or beyond range". | Cable too short; remote end connected. | Ensure cable is at least 4 meters long. Disconnect the remote end of the cable from any device or the receiver. |
| Scan function (toner) signal is weak or unclear. | Low sensitivity setting; interference; probe not close enough. | Adjust receiver sensitivity. Ensure probe is in direct contact with the cable. Avoid strong electromagnetic interference. |
| PING/IP Scan input is difficult. | Unfamiliarity with interface. | Practice using the Up/Down keys to navigate segments, OK to change numbers, and Back to confirm. |
| Tone generator does not work when cable is connected to a switch. | Some active network devices may interfere with toning signals. | Disconnect the cable from the switch before using the tone generator for tracing. |
9. Specifications
- Model: NF-859GK
- Dimensions: 6.5 x 3.5 x 6.5 inches
- Item Weight: 12 Ounces
- Cable Types Supported: CAT3, CAT5, CAT5e, CAT6, CAT6a, CAT7 (RJ45), RJ11
- Functions: TDR Cable Length Measurement, POE Test, PING Test, IP Scan, Port Flash, Continuity Test, Wire Tracing (Digital/Analog), Fiber Optic Continuity (VFL)
- TDR Measurement Range: 2.5m to 200m (8.2ft to 656ft)
- POE Standards: IEEE 802.3af/at detection
- Battery: Built-in 1500mAh 3.7V Lithium Battery
- Charging Port: USB Type-C
- Manufacturer: YILTION
10. Warranty
Specific warranty details are not provided in the product information. Please refer to your purchase documentation or contact the seller for warranty information.
11. Support
For any questions regarding product features, operational issues, test results, or general inquiries, customer service is available. You can expect online responses within 24 hours.