Apple MacBook Pro a2338 notebook is not powered on for repair

Machine model: apple MacBook Pro A2338

Board number: 820-02020

Malfunction: notebook water damage no booting

Maintenance process:

An Apple MacBook Pro A2338 notebook with a large area of water damage, which can be poured out when disassembled. After processing, the measurement is plugged in without boosting the voltage.

Apple MacBook Pro a2338 notebook is not powered on for repair Figure 1.
U5706 pin Short circuit,Current heating test found high temperature, the Typec chip in the upper left corner.Short circuit was removed, and U5700 3.8V chip was also broken.

After the replacement test, the boot sound is normal, and the screen is not displayed. Look carefully at the dark screen and find the definition of screen line interface.

Apple MacBook Pro a2338 notebook is not powered on for repair Figure 2.
PPVOUT_LCDBKLT does not boost 0V, screen VCC PP3V3_SW_LCD_CONN 3V is normal, and PP5V_SW_LCD_CONN 0V is abnormal. Repair 5V VCC first.

Apple MacBook Pro a2338 notebook is not powered on for repair Figure 3.
UP700 1 pin VCC is normal, 2 pin is turned on normally, 5 pin does not output, and pin is not measured. Connect it directly.

Apple MacBook Pro a2338 notebook is not powered on for repair Figure 4.
Start the test, the screen display is normal, troubleshooting, and maintenance is over.