Phase 1: Quick and intuitive inspection (non disassembly)

Appearance and connection inspection:

Sensor (probe): Check if the measuring needle is clean, severely worn or broken. Check if the guide head (if any) is worn or scratched. Check for obvious damage or bending of the probe cable.

Drive/Sliding Unit: Check if the sliding track is clean and free of foreign objects. Is the manual push smooth (in the event of a power outage).

Connection line: Ensure that all cables (sensors, drivers, power supplies) are securely connected to the host and corresponding interfaces.

Battery/Power: If using a battery, check if the power is sufficient. If using an adapter, make sure the socket is powered on.

Power on self-test and basic function testing:

After turning on, observe if there are any abnormal displays on the screen (such as garbled text, black screen, or missing displays).

Listen for any abnormal noise (such as stuttering or friction) when the drive starts.

Perform a simple 'empty run' test (without touching the workpiece, start measurement) to observe whether the driver can run at a constant speed normally.

Standard calibration test (the most critical step):

Use randomly attached standard roughness samples for calibration and measurement.

Perform the 'calibration' procedure for the instrument. If the instrument prompts calibration errors, out of tolerance, or if the measured value of the standard piece after calibration differs significantly from the calibration value of the standard piece (such as Ra 3.2 μ m) (for example, the error exceeds ± 10%), this is a clear signal of sensor or signal path failure.

If the calibration passes, but the results of measuring other known roughness workpieces are clearly unreasonable, it may also be a problem with the measuring needle or circuit.

Phase 2: Common fault phenomena and targeted troubleshooting

Fault phenomenonPossible reasonsTroubleshooting methods

The screen has no display/does not light up1. Battery depletion or power failure

2. Mainboard malfunction

3. Screen damage1. Connect the original charger for long-term charging, or replace the power supply.

2. Send for repair.

Startup error (Error code)Sensor, driver, or internal hardware error1. Refer to the explanation of error codes in the manual.

2. Common errors: probe not connected, driver stuck, internal memory error. Check the corresponding components according to the prompts.

Unstable measurement values and large fluctuations1. Wear or dirt on the measuring needle (common)

2. Oil stains and vibrations on the surface of the workpiece

3. Internal coil or circuit issues with the sensor

4. Poor grounding1. Clean the measuring needle (use specialized cleaning agent and a soft cloth to gently wipe along the direction of the measuring needle).

2. Clean the workpiece to ensure a stable measurement environment.

3. If it still bounces on the standard chip during testing, it may be a sensor malfunction.

4. Ensure that the instrument and workpiece are well grounded.

The overall measurement value is either too large or too small1. Wear of measuring needle radius

2. Calibration failure or uncalibration

3. Sensor sensitivity drift1. Use standard plates to recalibrate.

If the calibration is still inaccurate and the deviation is consistent, it may be that the sensor needs to be professionally calibrated.

Drive not moving or abnormal movement1. Mechanical jamming

2. Motor or drive circuit malfunction

3. Setting error (such as measuring length set to 0)After power off, check the track and clean it with anhydrous ethanol, manually push to ensure smoothness.

2. Check if the set parameters are correct.

If it still doesn't move, send it for repair.

Sensor (probe) has no signal1. Internal cable breakage

2. The internal coil of the probe is damaged

3. Host interface issues1. Slightly shake the cable connection and observe whether the signal is intermittent.

2. Replace a known normal probe for testing (if possible).

3. Send for repair and testing.

Phase Three: Advanced Diagnosis and Professional Maintenance

If the above steps do not solve the problem:

Factory reset: Try to reset the factory settings in the settings menu (note: all user settings and calibration data will be cleared), and then recalibrate the test. This can eliminate the problem of software setup confusion.

Isolation method judgment:

If you have accessories of the same model, you can try cross testing. For example, replacing a suspicious probe with another normal host, or replacing a normal probe with this host. This can quickly locate whether it is a probe issue or a host issue.

Environmental and operational review:

Ensure that the measurement conditions meet the requirements: temperature, humidity, and vibration.

Confirm that the measurement parameters (cut-off wavelength λ c, evaluation length ln, etc.) are set correctly and applicable to the surface being measured.

Final suggestion

Regular maintenance: Clean the measuring needle and guide rail after use, regularly calibrate with standard plates, and store in a dry and dust-free environment.

Refer to the manual: Sanfeng's user manual is a guide for fault diagnosis, which usually includes detailed error code tables and basic maintenance methods.

Seeking professional support:

Contact Sanfeng dealers or after-sales service outlets. This is a reliable way.

Provide detailed information: instrument model (such as SJ-410, SV-3000, etc.), serial number, fault symptoms, troubleshooting steps taken, error code photos or videos. This can help engineers make quick judgments.

Do not disassemble the sensor and the interior of the host by yourself, especially the sensor. The internal structure is precise, and non professional disassembly may cause damage.

Summary of troubleshooting process: Cleaning and observation → Standard film calibration testing → Refer to error codes → Check parameters and environment → Contact professional after-sales service.

According to this process, most faults can be located or resolved.