Lenovo Xinchao 7000-13 notebook has standby current without triggering multi-fault maintenance.

Lenovo Xinchao 7000-13 notebook has standby current without triggering multi-fault maintenance.

[Machine model] Lenovo Xiaoxinchao 7000-13

[Fault phenomenon] The notebook will not be triggered when there is standby current.

[maintenance process]

Repair a small trendy 7000-13 notebook computer with a standby current of 0.004. When disassembling the computer, it is observed that U6300 chip has been welded a little askew, U6001 chip has been welded (5V standby chip), and no obvious abnormality is found in other parts.

Lenovo Xinchao 7000-13 notebook has standby current without triggering multi-fault maintenance Figure 1

The first step of maintenance is to remove the inspection pads of the two chips that have been moved in the previous home and re-solder them. Make a common point-to-ground resistance value, big or short, and fix the big or short first. Burn the machine.

Lenovo Xinchao 7000-13 notebook has standby current without triggering multi-fault maintenance Figure 2

Sure enough, the capacitor next to the power supply tube of the video card is boiling hot, and the magnifying glass shows that it has changed color. The culprit is it. If it hadn’t been repaired at home, it would be time to call it a day.

Lenovo Xinchao 7000-13 notebook has standby current without triggering multi-fault maintenance Figure 3

After changing the capacitor, the standby 0.03 is normal. After pressing the switch on the keyboard, the white indicator lights up, and the single current becomes 0.01, which is normal after being triggered by +5V and+3.3V. It can be triggered, but the power supply of the system can’t go out. The resistance values are checked one by one, and no short circuit phenomenon is found. As the 5V standby is normal, it can be ruled out that the 5V chip repaired last home has no problem.

Focus on checking U6300 that was moved by the previous family, and measure the surrounding resistance against the drawings, and there is no abnormality. After careful analysis, if U6300 is not normal, it should be the lack of this group of voltages of 1.0V, and other voltages should be powered off, not powered off.

Lenovo Xinchao 7000-13 notebook has standby current without triggering multi-fault maintenance Figure 4

Since there is no power supply in the system, let’s start with the simplest one, find a 25Q64 to brush the program, change it, the boot current comes up, and restart it for 3 times to directly turn on the machine and enter the system. Troubleshooting, the maintenance is over.

Lenovo Xinchao 7000-13 notebook has standby current without triggering multi-fault maintenance Figure 5