Repairing Yamada 389-21-P Water Dispenser – No Cooling & No Power Issue Fixed
Today, we serviced a Yamada 389-21-P water dispenser, which had a cooling failure and no power output for the cold water indicator. The dispenser was not functioning properly, and we began troubleshooting to identify the issue.
Step 1: Inspecting the Cooling System
First, we removed the water filters and opened the back cover of the water dispenser cooling system. We noticed that the cooling fan was covered with dust, and the aluminum heat sink was clogged with dirt.
Diagnosing the Circuit Board
Using a tweezer bridge meter, we inspected the circuit board and found that a 47µF capacitor was damaged. This capacitor supplies power to the control chip, and if it fails, the cooling system will not function.
Yamada 389-21-P 饮水机维修：无电源输出与制冷故障修复
今天我们接到客户反馈，Yamada 389-21-P 饮水机的冷水指示灯不亮，没有电源输出，导致无法正常制冷。我们来检查并解决这个问题。
1. 设备检查与拆解
首先，我们取下滤芯，打开饮水机的后盖，检查内部的制冷总成。发现散热风扇和铝制散热片布满灰尘，可能影响散热效果。此外，我们使用镊子电桥测量电路板，发现一颗 47uF 电容 已损坏。
Step 2: Replacing the Faulty Capacitor & Cooling Fan
We carefully desoldered the damaged capacitor using a soldering iron and measured its value separately. The reading showed only 11.55µF, with a high dissipation factor (D value) of 1.4, confirming that it was completely faulty.
2. 电容损坏的影响
这颗电容负责给芯片供电，如果损坏，芯片无法启动，制冷系统也无法运行。我们使用烙铁拆除该电容，并单独测量其电容量。结果显示该电容 仅剩 11.55uF，D 值高达 1.4，说明电容已经完全失效。
Step 3: Reparing
To restore proper operation, we replaced the 47µF capacitor and also installed a new cooling fan.
3. 维修过程
我们更换了一个新的 47uF 电容，同时也更换了一个新的散热风扇，以确保系统能够正常散热。
Step 4: Testing the Cooling System
After reassembling, we powered on the dispenser and tested the cooling system. The clamp meter showed a DC current of 4.83A, indicating that the cooling process had started successfully, and the fan was running smoothly.
4. 测试与验证
更换配件后，我们重新通电测试。使用钳形电流表测量，直流电流达到 4.83A，表明制冷系统已经正常运行，风扇也开始运作。
Step 5: Additional Maintenance – Filter Replacement & Cleaning
Since the dispenser needed regular maintenance, we also:
- Replaced two water filters
- Cleaned the internal water tank
- Performed an external cleaning service
5. 额外清洁与滤芯更换
除了维修制冷系统，我们还进行了以下维护工作：
- 更换 2 支滤芯，确保饮用水的过滤效果。
- 清洗内桶，去除沉积物和杂质。
- 全面清洁机身，提升整体卫生标准。
Step 6: Final Temperature Check
Finally, we dispensed a cup of cold water and used an infrared temperature gun to check its temperature. The reading showed 20.6°C, meaning the cooling system was gradually lowering the water temperature, and the dispenser was working properly again.
6. 最终测试
我们取一小杯冷水，用温度枪测量温度，结果显示 20.6°C，温度已经开始下降，表明制冷功能恢复正常。这台 Yamada 389-21-P 饮水机已经成功修复，可以继续提供冷水了！
