MacBook A1502 notebook Won't Turn On for repair

MacBook A1502 notebook Won’t Turn On for repair

Machine model: MacBook A1502

PlateNo.: 802—4924-A

Malfunction: No matter whether the power supply or the battery is powered on, you can hear the sound auto power off.

Maintenance process: First, remove all peripherals, and the bare board test remains the same. After auto power off, the power-on fault remains the same. When you encounter this problem, you will definitely check the common terminal circuit first.

Q7180 double MOSFET G poles, the first MOSFET G pole is 7.4V, the second MOSFET G pole is 17V, which is wrong here, normally it is 7V or so, and this signal is controlled by ISL6259.

MacBook A1502 notebook Won’t Turn On for repair figure 1.

MacBook A1502 notebook Won’t Turn On for repair figure 2.

MacBook A1502 notebook Won’t Turn On for repair figure 3.

Under the working condition of 6259, 2 pin din is normal, 19 pin chip outputs five linear VCC from 19 pin, and 20 pin VDDP–after the linear VCC is normal, it is supplied to the chip itself VCC,VDDP through 20 pin, and VDDP is BOOTstrapped to boot inside the chip.

pin acin power adapter detects the signal. When ACOk is normal, 14 pin turns on the drain output, and 1 pin AGAET is low. When ACoK is normal, agaet is pulled low, and AGAET,AGAET is pulled low,MOSFET, the first P channel of PQ7180, is turned on.

SGATE should be low: when the first P-tube is turned on, the diode inside the second P-tube will turn on the adapter VCC of Low current, and then it will be applied to the upper tube of the charging chip through the precision resistor, and then it will reach the charging chip CSIP (adapter current detection anode) and CSIN (adapter current detection cathode) through both ends of the precision resistor. When CSIP CSIN is normal, SGAET will be pulled down inside the charging chip.Make that second p tube of PQ7180 produce large current VCC.