MacBook A1466 notebook fan has been repaired

MacBook A1466 notebook fan kept running, which was caused by corrode at the bottom of J4800 connector. The problem was fixed after replacement.

MacBook A1466 notebook fan has been repaired

Machine model: MacBook A1466

No. 820-00165

Fault symptom: no booting and DC power supply are 0.011A when you get it, and the notebook fan keeps running after the machine is repaired.

Maintenance process: judging from the current of DC power supply, it is found that the standby problem is weak after removing the board. After cleaning, it is found that SMC_RESET_L is only 0.3V According to the SMC_RESET_L signal, it is corrode at the bottom of R5100 pin. Replace R5100 to process PAD.

Stand by and power up Boot normally. After entering the system, it is found that the notebook fan keeps running. Reboot self-check error as shown in the figure:

MacBook A1466 notebook fan has been repaired

MacBook A1466 notebook fan has been repaired Figure 1.

The above error report VDH002 can be ignored, the error report caused by the memory Nand not installed when testing the machine, other error reports refer to the SMC system management problems, directly check the SMBUS bus of EC, and find that the SMBUS_SMC_3_SCL and SMBUS_SMC_3_SDA signals are abnormal.

MacBook A1466 notebook fan has been repaired

MacBook A1466 notebook fan has been repaired Figure 2.

From the drawings, we can see the waveform diagrams of abnormal SMBUS signals from EC to U5810 and J4800 interfaces, SMBUS_SMC_3_SCL and SMBUS_SMC_3_SDA.

MacBook A1466 notebook fan has been repaired

MacBook A1466 notebook fan has been repaired Figure 3.

MacBook A1466 notebook fan has been repaired Figure 4.

If EC U5000 is replaced directly, the fault remains, not the EC itself. U5810 and J4800 were checked, and it was found that corrode was at the bottom of J4800, and the drawing of J4800 corrode.

MacBook A1466 notebook fan has been repaired Figure 5.

The SMBUS_SMC_3_SCL and SMBUS_SMC_3_SDA signals are normal after replacing J4800 interface.

MacBook A1466 notebook fan has been repaired Figure 6.

MacBook A1466 notebook fan has been repaired Figure 7.

The installation test found that the fan was not running wildly, the speed was normal, and the running self-check was normal.

MacBook A1466 notebook fan has been repaired Figure 8.

Summary: The abnormal SMBUS_SMC_3_SCL and SMBUS_SMC_3_SDA signals caused by corrode at the bottom of J4800 interface will cause the fan to keep running, and PFM006 and PPN001 will be reported as errors during self-checking.