Introduction
This manual provides instructions for the proper setup, operation, and maintenance of the 125 C019 Telephone Phone Line Tester. This device is designed for professionals to efficiently check telephone line faults, identify caller ID, and perform basic line testing functions. Please read this manual thoroughly before using the product.
Package Contents
Verify that all items are present in the package:
- 1 x C019 Telephone Phone Line Tester (Blue)
- 1 x Phone Cable
- 1 x Connector Set (typically includes alligator clips and RJ11 plug)
Product Features
The C019 Telephone Phone Line Tester offers several key functionalities:
Telephone Line Fault Check
This device allows for quick identification of common telephone line faults, aiding in efficient troubleshooting.

Image: The C019 tester in hand, demonstrating its ability to check telephone line faults. The device is grey with a green digital display.
FSK/DTMF Dual System Caller ID and Redial Function
The tester supports both FSK and DTMF caller ID systems, allowing you to see incoming call numbers. It also features a redial function for the last dialed number.

Image: Two perspectives of the C019 tester, highlighting its display for caller ID and the redial button on the keypad.
Wire-receiving Function
This function assists in tracing and identifying specific wires within a bundle, simplifying cable management and troubleshooting.

Image: A detailed view of the C019 tester's earpiece, illustrating its wire-receiving function.
Equipped with 3 External Plug-in Heads
The tester comes with three external plug-in heads, providing versatility for connecting to various telephone line configurations.

Image: The C019 tester displayed with its included external plug-in heads, including alligator clips and an RJ11 connector.
Setup
- Unpack the Device: Carefully remove the C019 tester and all accessories from its packaging.
- Identify Connectors: Familiarize yourself with the phone cable and the external plug-in heads (RJ11 connector, alligator clips).
- Connect to Line: Depending on the type of telephone line or jack you are testing, connect the appropriate plug-in head to the tester's phone cable, then connect to the telephone line. Ensure a secure connection.
Operating Instructions
The C019 tester is designed for straightforward operation:
- Power On/Off: Locate the 'ON/OFF' switch on the device. Slide it to 'ON' to power the unit. The display should illuminate.
- Line Testing: Once connected to a telephone line, the device will automatically begin to detect line status. Observe the LCD display for information regarding line voltage, dial tone presence, or other fault indicators.
- Dialing: Use the numeric keypad to dial telephone numbers. This can be used to test line functionality or to make calls if the line is active.
- Caller ID: When an incoming call is detected, the caller's number will be displayed on the LCD screen (if the line supports FSK/DTMF caller ID).
- Redial Function: Press the 'REDIAL' button to redial the last number that was dialed from the tester.
- Flash Function: The 'FLASH' button can be used for call waiting or transferring calls, depending on the telephone system.
- Wire-receiving: For wire tracing, connect the tester to one end of the wire. Use the device's earpiece to listen for the signal when tracing the other end of the wire.
Maintenance
- Cleaning: Wipe the device with a soft, dry cloth. Do not use abrasive cleaners or solvents.
- Storage: Store the tester in a cool, dry place away from direct sunlight and extreme temperatures.
- Cable Care: Avoid sharp bends or excessive pulling on the phone cable and connectors to prevent damage.
Troubleshooting
- No Display/No Power:
- Ensure the 'ON/OFF' switch is in the 'ON' position.
- Check if the device requires batteries (though specifications indicate 'Corded Electric', some models may have internal rechargeable batteries or require external power for certain functions).
- No Dial Tone/Line Fault Indication:
- Verify that the phone cable and connectors are securely attached to both the tester and the telephone line.
- Test the line with a known working telephone to confirm the issue is with the line itself and not the tester.
- Ensure the correct type of connector is used for the specific telephone jack.
- Caller ID Not Displaying:
- Confirm that the telephone line service includes Caller ID (FSK/DTMF) functionality.
- Ensure the connection is stable during an incoming call.
Specifications
| Attribute | Detail |
|---|---|
| Model | C019 Wired Telephone Phone Line Tester |
| Brand | 125 |
| Item Model Number | Wendryriayobnfzg-01 |
| Color | Blue (Device in images is grey) |
| Material | ABS |
| Dimensions (L x W x H) | Approx. 14.7 x 4.6 x 2.2 cm (5.79 x 1.81 x 0.87 inches) |
| Item Weight | 133 grams (4.7 ounces) |
| Power Source | Corded Electric |
| Caller ID Support | FSK/DTMF Dual System |
Warranty and Support
For warranty information or technical support, please refer to the documentation provided with your purchase or contact the manufacturer directly. Keep your purchase receipt as proof of purchase.





