Yingchi GT630 black screen does not display repair

The black screen of the Yingchi GT630 does not display, and the NPN triode for power supply control is defective. After replacing the triode, all power supplies will normally generate a light.

Machine model: Yingchi GT630 black screen does not display

Fault phenomenon: black screen does not display

Maintenance process: The colleague sent a piece of GT630 in the evening. The colleague said that after a period of time, the power on screen did not show a black screen. First, hit the value to see if the gold finger 12V and 3V to ground values were normal, and the clock, reset and resistance values were normal. Then, measure the core power supply, video memory power supply and bus power supply resistance values were normal, which can be tested on the computer. After power on, it was found that 5V and 3V cores of the video card were powered out. There was no video memory power supply and no bus. According to the timing, the video memory should be powered out first. After measuring pin 7 of the video memory power supply chip, it was found that there was no open signal.

Yingchi GT630 black screen does not display repair Figure 1.

The open signal is controlled by the core power supply line running. It is found that the NPN triode controlled by the core power supply is defective. After the triode is replaced, all power supplies will normally generate a light.