MacBook A1932 water inlet fan turns wildly to deny battery repair

MacBook A1932 water inlet fan turns wildly to deny battery repair

Machine model: MacBook A1932

Fault symptom: it can be turned on, but the fan is spinning wildly.

Maintenance process: at first, I thought it was a peripheral problem, but I changed another set of chassis and the fault remained. I looked into the system and didn’t even recognize the battery. As soon as I pulled out the charger, I stood by.

MacBook A1932 water inlet fan turns wildly to deny battery maintenance. Figure 1

Apple’s online diagnosis found that there were two fault codes, the first was that the battery could not be identified, and the second was that SMC might be faulty, but Apple’s diagnosis could not explain any detailed problems.

MacBook A1932 water inlet fan turns wildly to deny battery maintenance. Figure 2

Dismantling the machine found that something was wrong near the battery seat and there was corrosion. This picture was taken later.

MacBook A1932 water inlet fan turns wildly to deny battery maintenance. Figure 3

Looking at it with an oscilloscope, the SCL pin of the battery is only 3.3V, but there is no waveform. This kind of problem should be difficult to find with a multimeter.

MacBook A1932 water inlet fan turns wildly to deny battery maintenance. Figure 4

After inspection, it was found that the battery socket was disconnected from Q6950 to R6951, and a wire flew to solve it.

MacBook A1932 water inlet fan turns wildly to deny battery maintenance. Figure 5

MacBook A1932 water inlet fan turns wildly to deny battery maintenance. Figure 6

MacBook A1932 water inlet fan turns wildly to deny battery maintenance. Figure 7

Apple’s design is too rubbish. T2 chip replaces the original SMC, so the information of battery power and temperature is managed by T2, but the I2C of T2 is 1.8V, and the battery is 3.3V, so Q6950 plays a role of signal amplification.