Lenovo Z485 serious water intrusion notebook does not turn on for repair

Lenovo Z485 serious water intrusion notebook does not turn on for repair

Machine model: Lenovo Z485

Fault phenomenon: notebook water damage no booting

Maintenance process: after being powered on, the standby 0.029 jumps by 0.000. I want to see that this current looks like Short circuit Current protection. Generally,large current has many jumps.
What if it’s a fortune Capacitor again?My heart secretly pleased, as soon as I opened the back cover, I found that the machine was not so simple.

Lenovo Z485 serious water intrusion notebook does not turn on for repair Figure 1.

This position is obviously into the beverage, after processing, continue to dismantle.Wait for me to take a look at the motherboard, the heart of ten thousand Grass Mud Horse flying, this also repair what?

Lenovo Z485 serious water intrusion notebook does not turn on for repair Figure 2.

If you want to burn a piece of corrode, you can’t get rid of it!

Lenovo Z485 serious water intrusion notebook does not turn on for repair Figure 3.

Jump wire was removed and the visible parts were repaired.

Lenovo Z485 serious water intrusion notebook does not turn on for repair Figure 4.

The power supply is still the same as before, and we carefully observe it again.

Lenovo Z485 serious water intrusion notebook does not turn on for repair Figure 4.

It was found that a hexagonal MOSFET pin was completely corrode, and PAD was also pasted into a lump. Fortunately, the drawing was found. It was known from the drawing that it was MOSFET,Change it on Parts motherboard.

Lenovo Z485 serious water intrusion notebook does not turn on for repair Figure 5.

Plug in the standby again. Press the power on key to get switch, but the current card does not move at 0.55 or so.

Lenovo Z485 serious water intrusion notebook does not turn on for repair Figure 6.

Test again found that the memory VCC did not come out, continue to check it!

Lenovo Z485 serious water intrusion notebook does not turn on for repair Figure 7.

It can be seen from the drawing that the model of memory VCC chip is tps51211. First test the 7 pin chip VCC. This test shows that there is a problem. Is there no power?According to the drawing, it is 5V VCC, passing through a 0 ohm resistor, an Capacitor GND, and then to the chip 7 pin. When measuring the resistance, the probe directly dropped. Originally,corrode below was disconnected, so I flew over again.

Lenovo Z485 serious water intrusion notebook does not turn on for repair Figure 8.

Hand held magnifying glass to make up memory VCC came out,switch current ran up, quickly installed test, finally booting up, maintenance is over.