格力GRJW843-A5 L3错误代码: Screenshot 2025-07-13 120829.jpg

Hello, I have a second motherboard with Gree GRJW843-A5 that has an L3 error code. I have tested all components and replaced the op amp U501 and the fan IPM. As for the components, I did not find any unusual resistors or capacitors in the IPM control and monitoring circuits. And all the lines are connected directly to where they should be. I have the schematic for this motherboard, so I followed it.




I also monitored the voltage from R304 to CPU-46 and the voltage from R34 to CPU-17. The voltage from R304 was normal at 3.3V. The voltage from R34 was initially 1.65V and gradually dropped over 30 seconds until the fan started to spin and the voltage dropped to around 1.2V and the fan stopped. After repeating this process 3 times, the AC tester showed L3.






I also changed all the capacitors to the values marked on the schematic, but the voltage drop problem persists. Has anyone experienced this with these Gree boards? I think this is an interesting discussion, and it seems to me that these boards are severely affected by the L3 issue. Please let me know what you think and if anyone can help.

Thanks in advance!!

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检查下风机模块后面的三个0.5欧电阻是否正常？更换为1欧的试下。