韩国采购需求：电池管理系统，BMS电池，BMS模块，锂BMS，BMS锂电池，适用于Lifepo4的BMS

I've purchased two units from your BMS range, and I've run into a significant issue. One unit is functioning flawlessly, while the other is completely unresponsive despite both being connected to the same battery pack. This discrepancy is puzzling, and I'm eager to find out what might be causing the malfunction. With an upcoming electric vehicle competition, time is of the essence for me. Any insights or troubleshooting steps you could share would be immensely helpful. I'm looking for guidance on potential fixes or diagnostics to quickly resolve this issue so I can ensure both units are operational before the event. Thanks for your assistance!