As a key equipment for studying transient spectra, the malfunction of laser flash photolysis directly affects experimental efficiency and data accuracy. Starting from the core module, the following outlines typical fault phenomena and targeted solutions:

1、 Power supply and startup abnormalities

Phenomenon: There is no response when pressing the start button, and the indicator light does not light up.

Troubleshooting steps:

1. Power supply inspection: Confirm that the power cord is firmly connected and the socket voltage matches the equipment requirements; Check if the fuse is blown, and replace it with the same specification and model if necessary.

2. Emergency stop button reset: Some devices are equipped with an emergency brake button, which may not start due to accidental triggering. Simply rotate it clockwise to reset.

3. Motherboard self-test: After disconnecting the load, test the output voltage of the power module separately. If there is any abnormality, contact the engineer to repair the circuit.

2、 Unstable or missing laser output

Phenomenon: Low laser energy, abnormal pulse width, or no laser output.

Key investigation points:

1. Resonant cavity misalignment: Slightly adjust the screw at the back of the resonant cavity (wearing protective glasses), observe the change in laser spot brightness, and restore it to the optimal focusing state.

2. Cooling system malfunction: The Nd: YAG laser requires water cooling for heat dissipation. Check if the circulating water pump is running properly, if the coolant level meets the standard, and if there are any blockages in the pipeline.

3. The lifespan of the krypton/xenon lamp is exhausted: After continuous operation for more than 500 hours, the luminous efficiency of the flash lamp significantly decreases, and a new lamp tube needs to be replaced according to the instructions.

4. Q-switch trigger delay: Adjust the synchronization time of the trigger signal to ensure that the pump light matches the timing of the Q-switch signal. The trigger waveform can be monitored through an oscilloscope.

3、 Signal acquisition failure or excessive noise

Phenomenon: The detector has no signal output, severe baseline drift, or low signal-to-noise ratio.

Root cause analysis and handling:

1. Decreased detector sensitivity: Prolonged exposure to strong light may cause cathode fatigue in photomultiplier tubes (PMT), which require shading and static recovery; If damaged, the same model of component needs to be replaced.

2. Optical path deviation: Re align the excitation light and detection light paths, confirm the beam path using an aligned paper target, and adjust the mirror angle to the optimal position.

3. Poor grounding: Check the grounding connection of the equipment to avoid high-frequency noise caused by electromagnetic interference; If necessary, add a shielding cover to isolate the external electromagnetic field.

4. Filter contamination: Dust adheres to the surface of the sample pool window or bandpass filter, causing stray light interference. Use lens paper dipped in ethanol to wipe it unidirectionally.

4、 Data collection system error

Phenomenon: The software prompts error codes such as "communication timeout" and "insufficient memory".

Emergency response plan:

1. Data cable reconnection: plug and unplug USB/Ethernet ports, replace with high-quality data cables; Check if the computer's COM port settings match the device's baud rate.

2. Driver reinstallation: Uninstall the original driver program, download the latest firmware and install it, compatible with the operating system version.

3. Cache cleaning: Close programs that occupy memory in the background and increase virtual memory allocation; Regularly delete temporary files to prevent storage overflow.

5、 Mechanical moving parts lag

Phenomenon: Delayed movement of the sample stage and abnormal motor noise.

Maintenance points:

1. Guide rail lubrication: Apply a small amount of silicon-based lubricating grease to the linear guide rail to avoid metal wear;

2. Belt tension adjustment: Loosen the fixing screw and horizontally move the synchronous belt tensioning wheel until there is moderate elasticity when pressed by fingers;

3. Limit switch calibration: Manually move the limit position and reset the travel limit parameters to prevent collision damage to the sensor.

6、 Preventive maintenance recommendations

-Daily: Before starting up, visually inspect all connecting cables and clean up any debris on the experimental platform;

-Weekly: Blow the surface of optical components with dry nitrogen gas and record the laser energy value;

-Monthly: Verify the dark current of the detector and check the sealing of the cooling system;

-Every year: Thoroughly disassemble and clean the optical cavity, replace aging rubber seals.

Through the above systematic troubleshooting, more than 90% of common faults can be solved. If it involves internal maintenance of the laser or debugging of the high-voltage module, it must be operated by certified technicians, and non professionals are strictly prohibited from disassembling it without authorization!