Repair of Dell G3590 laptop card

First use multimeter to measure and check the drawing. It is found that when the 1.8V display card core is VCC en pin(36 pin), the PWM chip ordered on the Internet arrives and the chip is replaced. After that, the display card runs normally after the machine is repaired and the maintenance is over.

Machine model: Dell G3 3590

Fault phenomenon: the display card recognizes the time but does not recognize it

Maintenance process: it is invalid to reload the system, swipe BIOS and replace the high wattage adapter. After the video card is not recognized in the system, it is necessary to restart n times before recognizing it once with low probability. It is difficult to measure the condition.

Dell G3 3590 notebook unrecognized graphics card maintenance Figure 1

When identifying the display card, both the measurement display card VCC and the display memory VCC are available. After the system does not recognize the display card,VCC is not available, so it is unable to measure whether the display card is opened normally.There is a timing diagram of the graphics card in the drawing, which follows the old tradition of NVIDIA. It is roughly like this: 1.8V > core VCC> video memory VCC.

Dell G3 3590 notebook unrecognized graphics card maintenance Figure 2

Dell G3 3590 notebook unrecognized graphics card maintenance Figure 3

First measure with multimeter, 1d8v_VGA_S0 is the EN used to pull up the chip VCC, which is not available when it is not recognized, 1d8v_VGA_S0 is composed of 1d8v_ANY_From S0.

Dell G3 3590 notebook unrecognized graphics card maintenance Figure 4

Because the measurement time is 1d8v_ANY_The opening of S0 at 3.3V was also sometimes absent. At that time, it was detected that the opening was available, and then Inductor was not detected. It was thought that 1.8V was not generated.

Dell G3 3590 notebook unrecognized graphics card maintenance Figure 5

multimeter e chip of q8601.8v is removed, it will be difficult to identify the chip multimeter e chip is small.

Dell G3 3590 notebook unrecognized graphics card maintenance Figure 6

Then I went to Xinzhizao Soft to check the drawings and found that the 1.8V display card core VCC en pin(36 pin) was turned on. To my surprise, the chip VCC of the graphics card was turned on all the time, and pwm1, pwm2 and pwm3 were measured to VCC.

Dell G3 3590 notebook unrecognized graphics card maintenance Figure 7

Dell G3 3590 notebook unrecognized graphics card maintenance figure 8

If I enter the system again, it will change into a graphics card sometimes not in the system. I also make it convenient to measure, instead of losing the card, I can no longer recognize it. When the display card can recognize it, pwm1, pwm2, pwm3,pin of the display card chip send out the regular waveform of less than 1V, and the front end of the PWM chip of the later stage will also have waveform.When it is not recognized, it sends out 1.5V DC. Now that the conditions of VCC chip are met, it is reasonable to suspect the PWM chip itself.

Dell G3 3590 notebook unrecognized graphics card maintenance Figure 9

When the PWM chip ordered on the Internet arrived and replaced the chip, the display card could be recognized normally after the chip was turned on again. The removed q8601 can still be recognized. When the machine is repaired, the display card runs normally, and the maintenance is over!

Dell G3 3590 notebook unrecognized graphics card maintenance Figure 10