Maintenance of unrecognized graphics card for Dell G3 3590 notebook

Dell model G3590

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

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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.

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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

As a result, when a 1.8V chip is replaced, the result is still the same, sometimes not. At this time, it is really difficult to measure the conditions. Sometimes there will be a short time, and the multimeter may not be stuck. The removed q8601 is equivalent to directly pulling up 3V of 1.8V en, so that 1.8V has been available, but the graphics card will still not recognize it.

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VCC time, when you turn on the VCC, you will find that the core of the VCC is turned on from the pin o the Xinzhizao Soft.

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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