Acer E5-471 Notebook Won't Turn On repaired

Acer E5-471 Notebook Won’t Turn On repaired

Machine model: Acer E5-471
Malfunction: Notebook Won’t Turn On

Maintenance process: after the USB device is connected, it will be no booting. After disassembling the machine, it is found that there is no obvious Short circuit, and the standby mode has come out. Press Switch, and switch moves from 0.00 to 0.01, and then it falls off quickly. Or switch again, and directly find the drawings.

Acer E5-471 Notebook Won’t Turn On repaired Figure 1.

The machine has come out of EC, and the height of the bridge is normal. No S3 and S4 are available, and it’s back to the standby of the South Bridge.

Acer E5-471 Notebook Won’t Turn On repaired Figure 2.

When I found that everything was normal, I thought the CPU wouldn’t really hang up, right? Since the USB is plugged in, there is no Short circuit in the data of the USB interface, and VCC is not Short circuit, so it goes back to the South Bridge for standby, and VCCSUS3_3 is this discovery.

Acer E5-471 Notebook Won’t Turn On repaired Figure 3.

However, pressing Switch instantly found that it came out, and S5_ON from EC was turned on. Since this came out to control the standby of the South Bridge, did the machine have switch, and then it was detected that it dropped abnormally. As a result, it became obvious when it was turned on the oscilloscope.

Acer E5-471 Notebook Won’t Turn On repaired Figure 4.

1.5V came out, then auto power off.

Acer E5-471 Notebook Won’t Turn On repaired Figure 5.

Moreover, bus VCC also came out. After some time, it was found that CPU VCC didn’t, and there should definitely be another VCC that didn’t, and then it ran to the subsequent conversion to find the problem. The conversion VCC is caught out in this way, which is definitely not normal. One VCC found the problem, handled it and installed it directly for testing.