Repair of Lenovo E460 laptop dark screen

Lenovo E460 laptop turned on the dark screen and began to dismantle the screen. It was found that Capacitor,Short circuit and Fuse around the screen booster chip were burnt out. The Current heating test method was used, and 3V VCC Current heating test was added to the back stage of Fuse. After touching the boost chip, it was hot to remove it. It was found that Short circuit was eliminated, and the screen was delivered directly. The new screen was replaced and the fault was solved.

Machine model: Lenovo E460 notebook

Fault phenomenon: Lenovo E460 laptop standby current 0.009, power on after dark screen, you can see the boot screen.

Maintenance process:
Open Xinzhizao Soft software to view the drawing.Check the three conditions, screen VCC, screen open,GND good, measured 1 pin 18.7v;6. 7, 9 pin 3.3V, backlight on 11 pin bkoff ා is 0V;

Lenovo E460 laptop boot dark screen maintenance Figure 1

Check that the backlight source is ec119 pin, and there is no disconnection,Short circuit,diode value 566,or so. A 3.3V forced high is found on the main board, and the test is still dark screen.

Lenovo E460 laptop boot dark screen maintenance Figure 2

Lenovo E460 laptop boot dark screen maintenance Figure 3

Now that the conditions are met, lock the fault point on the screen.Starting to dismantle the screen, it was found that Capacitor,Short circuit and Fuse around the booster chip were burnt out. After removing it, a good test was carried out, and it was found that the screen was still dark.

Lenovo E460 laptop boot dark screen maintenance Figure 4

Lenovo E460 laptop boot dark screen maintenance Figure 5

After measuring again,Fuse is burned again. Use Current heating test method, add 3V VCC Current heating test to the rear stage of Fuse. Touch the booster chip and remove it. If Short circuit is found to be eliminated, it will be delivered directly to the fixed screen, and the new screen will be replaced. The work will be finished perfectly and the fault will be solved.