Asus A456U notebook will not be started up for repair when water enters.

Asus A456U notebook will not be started up for repair when water enters.

Machine model: ASUS A456U notebook

Main board number: X456UQK 2.0

Fault phenomenon: the notebook does not boot when it is flooded.

Maintenance process:

Received an ASUS A456U notebook computer, and the whole motherboard was seriously corroded by water.

Asus A456U notebook water does not boot maintenance Figure 1

Open Xinzhizhao, check the maintenance instructions and PDF drawings.

Asus A456U notebook water does not boot maintenance Figure 2

Deal with the corroded circuit.

Asus A456U notebook water does not boot maintenance Figure 3

Simply measure the motherboard before powering on.

Asus A456U notebook water does not boot maintenance Figure 4

The resistance value of the measured memory 1v2 inductor voltage to the ground is 0. Disconnect JP8602 to confirm that the load terminal is short-circuited and the machine is burned, and two memory particles are severely burned.

Asus A456U notebook water does not boot maintenance Figure 5

There is another one on the other side. This one is DDR4 4G onboard memory composed of 8 particles.

If you don’t have the same particles on hand, change your maintenance thinking and remove all the shielding onboard memory.

Asus A456U notebook water does not boot maintenance Figure 6

The motherboard is provided with an external memory slot (provided that the half-load memory line must be masked first). The first method is to modify the BIOS mask, and the second is to change the hardware settings.

The method of changing the resistance shielding memory provided by netizens, but it was not successfully modified, and there was still no memory current when it was powered on. It was also not solved by brushing the original BIOS.

Asus A456U notebook water does not boot maintenance Figure 7

Try to change different memory modules for many times. The last 4G memory module can be turned on normally, but the screen will be blue after a while, and the 8G memory module cannot run through the memory normally.

When the memory particles arrive, stick 8 on-board memory particles, and change back the on-board memory identification resistor at the same time. After installation test, the memory current is also insufficient.

Asus A456U notebook water does not boot maintenance Figure 8

The external memory of the machine can light up and enter the system, indicating that most circuits have been working normally. Measuring the memory power supply circuit accessories, it is found that the memory voltage of 0.6V is only 0.14V

Asus A456U notebook water does not boot maintenance Figure 9

This may be the reason why you can’t recognize the external 8G memory module and the blue screen will appear soon after entering the system.

Search APW6002 chip data and check the schematic diagram.

Asus A456U notebook will not be turned on for maintenance when water enters Figure 10

Measuring that 5# s5 and 6# s3 are turned on normally, except that the voltage of 0.6V is not available, and the load is not short-circuited, indicating that the APW 6002 chip is broken. Change the line, move it greatly, and move this circuit on another board here.

This circuit is relatively simple, with 1.2V input and 5V auxiliary power supply. s3 is selected when it is turned on.

Asus A456U notebook will not be turned on for maintenance when water enters Figure 11

Installation test, normal lighting of the machine into the system, and no blue screen, troubleshooting.

Asus A456U notebook will not be turned on for maintenance when water enters Figure 12