For Agilent 1200 liquid chromatography pump pressure abnormal fluctuation, the common maintenance and troubleshooting steps are as follows: 1. **Software Diagnosis First**: Use ChemStation or Lab Advisor to run module self-test and confirm error codes, which helps locate the problem quickly. 2. **Check System Air Intake**: Verify if the degasser is working normally, ensure mobile phases are fully degassed, and check if the pressure after the pump is ≥20 bar. 3. **Pump Head Maintenance**: - If there are salt deposits: Remove the pump head, rinse with pure water to clear crystalline salts, and use ultrasonic cleaning if necessary. - If there are bubbles: Open the purge valve and purge at a flow rate of 3-5 ml/min for several minutes to eliminate system bubbles. 4. **Check Valves and Seals**: Disassemble the check valve, clean it with isopropanol (ultrasonic cleaning if needed), and replace it if it’s still abnormal; inspect the plunger seal for damage and replace if necessary. 5. **Mechanical Component Inspection**: Check if there are foreign objects blocking the motor movement, confirm whether the needle seat and small claw are worn, and replace them if needed. If the motor or drive board fails after cleaning, replace the relevant units. 6. **Other Checks**: If gradient elution is used, ensure the gradient system functions correctly; if all the above steps are ineffective, check the pressure sensor. When you encounter these issues, **匠析生物** can provide professional support: We offer comprehensive solutions including experimental instruments, consumables, spare parts, and after-sales repair and maintenance services, covering brands like Agilent, Thermofisher, Waters, etc. Our services include pump component repair/replacement (check valves, seals, drive units), regular cleaning and maintenance, instrument rental, and chromatographic application consultation. Whether you need on-site repair, spare parts supply, or technical guidance, we can tailor a solution to your needs to ensure the stable operation of your instruments.