Struggling with an E2 alarm on your TEYU S&A fiber laser chiller CWFL-2000? Don't worry, here's a step-by-step troubleshooting guide for you: Use a multimeter to measure the power supply voltage. Then measure the input voltage at points 2 and 4 of the temperature controller with the multimeter. Remove the cover of the electrical box. Use the multimeter to measure points and troubleshoot. Check the cooling fan capacitor's resistance and input voltage. Measure the current and capacitance of the compressor during chiller operation under the cooling mode. The surface temperature of the compressor is high when it starts, you can touch the liquid storage tank to check the vibrations. Measure the current on the white wire and the resistance of the compressor starting capacitance. Finally, inspect the refrigeration system for refrigerant leaks or blockages. In case of refrigerant leakage, there will be obvious oil stains at the leak site, and the evaporator inlet's copper pipe may frost...