Win7 System computer power-on after the failure of the black screen

1, take apart the chassis found that the power supply fan does not turn, the touch of the shell found very hot, suspected to be caused by power failure, the power supply from the chassis removed further inspection;

Win7 system computer power off black screen after boot

2, remove the power supply the surface of the four corners of the screws down, the shell removed, the fan connection from the power supply board to pull down;

3, the power output line through the shell from the shell to take off, will be exported from the shell to remove;

4, using a multimeter to measure the fan, after testing the normal fan, and then check the power supply board fan power supply voltage, measured without output voltage;

5, the power supply board screws down the Four corners, the motherboard from the shell to take down further inspection;

6, because the fan does not supply voltage, determined that because the fan stopped, causing the power supply temperature rise, voltage protection stopped working computer black screen, around the fan power supply wind to find the relevant original, found one of the resistance virtual welding;

7, with electric soldering iron components after welding power test machine, power supply fan restored rotation, the power supply board, fans, etc. in order to install the power to reinstall the computer host, after the computer running for six hours and no black screen, since the power failure caused by the blackout black screen troubleshooting.