1. Introduction
The UNI-T UT665 Borescope Industrial Endoscope is a versatile inspection tool designed to provide clear visual access to hard-to-reach areas. It features a flexible camera probe and a display screen, making it ideal for non-destructive testing in various environments, including automotive engines, industrial pipelines, inner building walls, and drain pipes.
This manual provides essential information on the safe and effective use of your UT665 borescope, covering setup, operation, maintenance, and troubleshooting.

2. Safety Information
Please read and understand all safety instructions before operating the device. Failure to follow these instructions may result in injury or damage to the device.
- Do not use the device in explosive atmospheres or near flammable gases.
- Keep the device away from strong magnetic fields.
- Ensure the battery compartment is securely closed to prevent water ingress, especially when using the waterproof probe in liquids.
- Do not attempt to disassemble or modify the device. Refer all servicing to qualified personnel.
- Clean the probe and lens carefully after each use to maintain optimal performance.
3. Package Contents
Verify that all items are present in the package:
- UNI-T UT665 Borescope Main Unit
- Flexible Camera Probe (1 meter length)
- User Manual

4. Product Overview
The UT665 borescope consists of a main unit with a display and controls, and a detachable flexible probe with a camera and LED lights. Refer to the diagram below for component identification.

Main Unit Controls:
- Display Screen: 2.4-inch TFT screen (480x234 pixels) for real-time viewing.
- Power Button: Turns the device on/off.
- LED Light Adjustment Button: Adjusts the brightness of the probe's LED lights (4 levels).
- Image Rotation Button: Rotates the image on the screen by 180 degrees.
- Probe Connector: Port for attaching the flexible camera probe.
- Battery Compartment: Holds four AA batteries.
Flexible Probe:
- Camera Lens: 9mm diameter, with a focal length of 20mm-100mm.
- LED Lights: Integrated lights around the camera for illumination in dark areas.
- Waterproof Rating: IP67, allowing submersion in water.
5. Setup
5.1 Battery Installation
- Locate the battery compartment on the back of the main unit.
- Open the battery compartment cover.
- Insert four (4) AA batteries, ensuring correct polarity (+/-).
- Close the battery compartment cover securely.
5.2 Attaching the Camera Probe
- Align the connector of the flexible camera probe with the probe connector port on the main unit.
- Gently push the probe connector into the port until it clicks into place.
- Ensure the connection is firm to prevent accidental disconnection during use.
6. Operating Instructions
6.1 Powering On/Off
- To Power On: Press and hold the Power button (⏻) until the display screen illuminates.
- To Power Off: Press and hold the Power button (⏻) again until the display turns off.
6.2 Adjusting LED Lights
- While the device is on, press the LED Light Adjustment button (💡) to cycle through the 4 brightness levels of the probe's LED lights.
- Select the appropriate brightness for optimal visibility in the inspection area.
6.3 Image Rotation
- To adjust the orientation of the image on the screen, press the Image Rotation button (△).
- Each press will rotate the image by 180 degrees, allowing for comfortable viewing regardless of the probe's orientation.
6.4 Performing an Inspection
- Carefully insert the flexible probe into the area you wish to inspect.
- Guide the probe by manipulating its flexible shaft.
- Observe the real-time image on the display screen.
- Adjust the LED light brightness as needed for clear visibility.
- Use the image rotation function if the image appears upside down or sideways.
- When finished, gently withdraw the probe from the inspection area.

7. Maintenance
7.1 Cleaning
- Probe: After each use, especially in dirty or wet environments, wipe the probe and camera lens with a soft, damp cloth. For stubborn grime, a mild detergent can be used, followed by a clean, damp cloth. Ensure the probe is dry before storage.
- Main Unit: Clean the main unit and display screen with a soft, dry cloth. Do not use abrasive cleaners or solvents.
7.2 Storage
- Store the borescope in a cool, dry place, away from direct sunlight and extreme temperatures.
- If the device will not be used for an extended period, remove the batteries to prevent leakage.
- Avoid bending the flexible probe sharply or storing it in a kinked position to prevent damage.
8. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Device does not power on. | Low or dead batteries. Incorrect battery installation. | Replace with fresh AA batteries. Check battery polarity. |
| No image on screen. | Probe not connected properly. Camera lens is dirty or obstructed. | Ensure the probe is securely connected. Clean the camera lens. |
| Image is too dark/bright. | LED brightness not adjusted. | Press the LED Light Adjustment button to cycle through brightness levels. |
| Image is upside down/sideways. | Probe orientation. | Press the Image Rotation button to adjust the image orientation. |
| "Not connected" prompt appears. | Probe is not detected. | Check the probe connection and ensure it is fully inserted. |
9. Specifications
| Feature | Specification |
|---|---|
| Product Model | UT665 |
| Pixel | 300,000 |
| Screen Size | 2.4 inches |
| Screen Resolution | 480x234 |
| Lens Focal Length | 20mm - 100mm |
| Coiled Tube Length | 1 meter |
| Lens Diameter | 9mm |
| Protection Grade (Probe) | IP67 (Waterproof) |
| Image Brightness Adjustment | 6 Levels |
| LED Lamp Brightness Adjustment | 4 Levels |
| Video Recording | N/A (Not available) |
| Image Rotation | 180 degrees |
| Power Display | Yes |
| Not Connected Prompt | Yes |
| Power Supply | Four AA batteries |
| Certifications | CE |
10. User Tips
- For optimal viewing, ensure the inspection area is adequately lit using the probe's adjustable LED lights.
- When inspecting narrow or complex spaces, gently maneuver the probe to avoid damaging the camera lens or the probe itself.
- Regularly check battery levels, especially before critical inspections, to avoid interruptions.
11. Warranty and Support
The UNI-T UT665 Borescope Industrial Endoscope comes with a one-year warranty from the date of purchase. This warranty covers manufacturing defects and malfunctions under normal use. Please retain your proof of purchase for warranty claims.
For technical support, service, or warranty inquiries, please contact your retailer or the manufacturer's authorized service center.





