Lenovo rescuer y7000 notebook does not recognize unique repair

Model: Lenovo Savior Y7000

Main board number: NM-B961

Fault phenomenon: the notebook does not recognize the unique display.

Maintenance process:

Saver Y7000 laptop, the fault is that the laptop doesn’t recognize the independent display, the graphics card is 1060, and all other functions are normal. Disassemble and measure that the VCC NVVDD, the core of the graphics card, has 0.8V when it is turned on, and the current drops from 1.2 to 0.7A The core VCC chip is RT8813, and the measurement is turned on instantly. Brush the BIOS, and the fault remains the same. 060 graphics card adopts three-phase VCC with 6 composite VCC in total, but it still doesn’t work in groups.

Lenovo rescuer y7000 notebook does not recognize unique repair Figure 1.
After booting for many times, you will find that the occasionally booted graphics card VCC is all normal, and you can recognize the 1060 graphics card when you enter the system, eliminating the core damage. Other VCC,1.8V and PEX DVDD’s 1.0V graphics cards are also available for instant power-on measurement, except NVVDDS(0.8V) and 1.35V video memory.VCC CPU1801 video memory only has screen printing, but the chip model can only be checked from NVVDDS VCC chip.

Lenovo rescuer y7000 notebook does not recognize unique repair Figure 2.
The NVVDDS chip is NCP81278, and the boot graphics card VCC auto power off is too fast to measure with multimeter. The memory is unplugged and booted, so the graphics card core VCC stably outputs 0.8V All conditions of NCP81278 chip are normal, except that it doesn’t output NVVDDS VCC 0.8V After the chip is replaced, the output of 0.8V is stable, and the current can’t drop more than 1A. After entering the system, the graphics card normally identifies and displays VCC 43, and it is brushed back to the original BIOS, and the graphics card has been driven normally.There is no problem running 3D. Troubleshooting, the maintenance is over.