MacBook Air A1465 laptop cannot be powered on for repair

Machine model: MacBook Air A1465

PlateNo.: 820-00164-A

Malfunction: Notebook Won’t Turn On

Maintenance process: the little green light for plug-in is not on. After disassembling the machine, there are 8.5V or so,PP3V42_G3H, and there is no 3/5V for standby. Normally, there should be 3V VCC for standby, and the standby chip is TPS51980A.

Simple measurement shows that VIN, EN, G5, VREG3 VCC are available, but P3V3_S5_EN_R of EN2 turns on VCC, which is ultimately M2 pin connected to EC.

MacBook Air A1465 laptop cannot be powered on for repair Figure 1.

MacBook Air A1465 laptop cannot be powered on for repair Figure 2.

Measurement did not send EN, measured EC standby conditions, and the previously generated PP3V42_G3H was given to VBAT, VDD, VDDA pin VCC of EC. After obtaining VCC, the 12M VCC oscillation of EC provided the benchmark Crystal frequency for EC. When the reset was measured, an abnormality was found.

MacBook Air A1465 laptop cannot be powered on for repair Figure 3.

This signal is pulled up by R5100, and the measured value is only 0.7V or so. The reset comes from the 5th pin of U5110, but the measured value is 3.3V VCC. Finally, it is determined that the VCC is pulled down inside the EC (because more than 500 or so to the ground is within the normal range, it should only be that the EC itself is broken).

MacBook Air A1465 laptop cannot be powered on for repair Figure 4.

Replacing EC can be normal.switch is shown on power, thinking the story is overActually, it’s just beginning. Because this EC is programmed, and the board number should be checked. Although the machine can be turned on normally, it has the following faults: 1. The little green light is not on. 2. No sound. 3. The picture runs abnormally, with only 4MB of video memory.

MacBook Air A1465 laptop cannot be powered on for repair Figure 5.

At that time, I bought two pieces of disassembly EC and replaced one piece, and the result was exactly the same. Because EC is packaged by BGA Rework Station, it is suspected that Inveracious Soldering was reinstalled by REBALLING, and the fault remains. Finally, finally, finally solve the problem.

PS: Buy Parts motherboard directly, remove EC and replace it. Forget it. I downloaded EC REBALLING no less than six times, and my eyes were wasted. Facts have proved that the EC purchased before is the same model, but it should be a different board number, which further shows that Apple is really abnormal.