Lenovo xiaoxinchao 7000-13 notebook is not powered on for repair

Machine model: Lenovo xiaoxinchao 7000-13

Fault phenomenon:no booting without standby laptop when powered on no power on. Lenovo Xinchao 7000-13, plug-in adjustable power on no power on, no standby.Remove the back cover, unplug the COMS battery and power on again later. The fault is still the same.After measuring the whole motherboard Inductor, there was no obvious Short circuit. After power on measurement, it was found that there was no 3v5v. After looking for the drawing, it was found that the Current protection isolation tube of this machine was n-tube. The physical measurement was found on the board.

Lenovo xiaoxinchao 7000-13 notebook is not powered on for repair Figure 1.

Follow Boardview.

Lenovo xiaoxinchao 7000-13 notebook is not powered on for repair Figure 2.

Lenovo xiaoxinchao 7000-13 notebook is not powered on for repair Figure 3.

Find out that the physical measurement is normal, and the first MOSFET is not completely connected. Check which chip controls the G pole of the isolated Current protection tube.Continue to trace the 1 pin of the charging chip without VCC, and measure the resistance Diode value is normal,Capacitor is normal,diodeNo, the pros and cons are 580.

Lenovo xiaoxinchao 7000-13 notebook is not powered on for repair Figure 4.

Replace d5901, the plug-in current is out, but DC power supply, the current lamp flashes or short.

Lenovo xiaoxinchao 7000-13 notebook is not powered on for repair Figure 5.

After Measuring diode value, it was found that the whole board Inductor was still normal. There was no obvious Short circuit. Some people said that it was the screen interface Short circuit.

Lenovo xiaoxinchao 7000-13 notebook is not powered on for repair Figure 6.