Acer E5-471 Laptop Does Not Turn On

 

Laptop Model: Acer E5-471

Symptom: Laptop Does Not Turn On

Maintenance Process:

The Laptop stopped turning on after connecting the USB device. At this time, I thought it might be that the USB device was down, right? 

Then why repair it? I directly dismantled it and found that there was no clear short circuit, and the standby function was still out. When I pressed the switch, I found that there was a triggering action, 0.00 to 0.01, and then it dropped quickly, and it was triggered again. I directly found the drawing.

I found that the EC had come out of the Laptop, and the height of the bridge was normal, so the next step was S3 and S4. After checking that they were not there, I ran to the standby of the south bridge.

After checking, I found that everything was normal. At this time, I thought that the CPU was not really dead, right? In this case, there is no need to practice. 

Since we are checking for USB burn, we check that there is no short circuit in the data of the USB interface, and there is no short circuit in the power supply, so it returns to the south bridge standby.

This is the result of the discovery that VCCSUS3_3 is not there.

But when I pressed the switch, I found that it came out, and turned on the S5_ON from EC. Since this comes out to control the south bridge standby, has the Laptop been triggered, and then detected an abnormality and dropped it? The result is obvious when I put it on the oscilloscope.

1.5V came out and then powered off.

And the bus power supply also came out. After some research, I found that the CPU power supply was not available. There must be another power supply, and then I rushed to the subsequent conversion to find the problem.

 If the converted voltage is like this, it must be abnormal. Once the problem is found, it can be installed and tested directly after the problem is solved.

The Laptop lights up normally and the maintenance is completed.

Happy Repairing !!