Lenovo Y7000 notebook water damage boot screen is black or frozen repair

Machine model: Lenovo Y7000
Main board number: NM-C221 Rev:2.0
Malfunction: notebook water damage starts screen is black or frozen.

Lenovo Y7000notebookComputer, the fault is that screen is black or frozen is turned on, and the external HDMI display is normal.

Lenovo Y7000 notebook water damage boot screen is black or frozen repair figure 1.
Dismantling, screen FPC part Oxygenation corrode is serious, and the gold finger on FPC falls off a lot. This screen is a 30-pin EDP screen.multimeter runs the line and finds the location of the corresponding power cord on the motherboard. The golden finger of the screen FPC with backlight has been completely corrode.corrode comes out on FPC FPC, and the measured screen logic FPC VDD VCC is only 0.2V.

Measure the VDD position of VCC on the main board end. The diode to ground is 0.091. There is Short circuit. There is a 5 pin MOSFET on the back of the motherboard which gives the screen VCC 3.3V. It is burnt out.

Lenovo Y7000 notebook water damage boot screen is black or frozen repair Figure 2.

Remove the broken MOS, Jump wire,short-circuit input and output, and measure the VDD output again. The ground value is 0.390, which is normal.

Lenovo Y7000 notebook water damage boot screen is black or frozen repair Figure 3.
Deal with the serious screen wire of corrode, and Jump wire leads to VLED backlight VCC.

Lenovo Y7000 notebook water damage boot screen is black or frozen repair Figure 4.
Connect the backlight VCC directly Jump wire to the common point VCC(+ 20V) entering the upper tube of CPU.