Colorful GTX1050 graphics card does not display repair

Graphics card model: Colorful GTX1050 Smart Shark 2GD5 graphics card

Symptoms: The graphics card does not display.

Maintenance process:

A colorful GTX1050 graphics card, the fault is that the boot is sometimes displayed and sometimes not displayed, and it will not be displayed once it is restarted occasionally.

Colorful GTX1050 graphics card does not display repair figure 1.
Test basic VCC, core VCC 0.75V, video memory VCC 1.5V, first auxiliary VCC 1.05V, second auxiliary VCC 1.8V.

Colorful GTX1050 graphics card does not display repair figure 2.
The first core VCC,VCC chip is RT8813D main VCC, 3 pin EN 1.0V, and sometimes the graphics card can display it. During the first display, the measured value of EN pin VCC is 3.3V, indicating that the measured value of En pin.0V is abnormal and low when it is not displayed.
After running the route, I drew a picture of EN’s generation schematic by hand.

Colorful GTX1050 graphics card does not display repair figure 3.

Colorful GTX1050 graphics card does not display repair figure 4.

As can be seen from schematic, the core VCC comes out first, the 3rd pin en of core VCC chip RT8813D comes from D5, the VCC chip RT8071 of 1.05V auxiliary VCC, and the 10th pin en are made up ofgating circuitU3 4th pin, and this EN is controlled by the EN of the core VCC chip, which is caused by the failure of Q584.

Replacement installation test shows that it is normal.