IPad Air3 A2134 startup dark screen without backlight repair

IPad Air3 A2134 startup dark screen without backlight repair

The measured voltage, inductors L82P0, L82R0 and diode D820D82P0 are all supplied with VCC 4V, but there is no boost. The large inductor and two diodes are directly replaced, and the base is back to 500, which is normal.

Machine model: iPad Air3 A2134

Fault symptom: No backlight on the dark screen.

Maintenance process:

An iPad Air 3 fell, it can be turned on, and the Apple LOGO can be seen vaguely, and there is a sound when the charger is plugged in.

IPad Air3 A2134 boot dark screen without backlight maintenance figure 1

Replace the screen, or dark screen, then the problem lies in the motherboard. Remove the shield, observe it under the microscope, and find the fault point instantly.

IPad Air3 A2134 boot dark screen without backlight maintenance Figure 2

Two diodes were punctured, so the diodes were directly removed, and the test found that the back pole was short-circuited.

IPad Air3 A2134 boot dark screen without backlight maintenance Figure 3

Burning machine, there is no hot place. When the capacitor C82R4 is removed from the line, it is not short-circuited and the capacitor is broken down. Find two diodes to install, and the test is still dark.

The measured voltage, inductors L82P0, L82R0 and diode D820D82P0 are all supplied with VCC 4V, but there is no boost. Dismantle an inductor on the Samsung material board and replace it with it, and it will be hot directly.

IPad Air3 A2134 boot dark screen without backlight maintenance Figure 4

Find the same one and put it on, but it’s still hot. I found that the resistance of pins 14 and 26 is only 280, but it’s actually 480. Looking down these two feet, I found that the diode D82P0, which was just hot, had the same resistance at both ends, and was broken down again. Then I changed the diode and buckled the screen to test, and both diodes were hot and broken down again. Directly replace the large inductor and two diodes, and the seat is back to 500, which is normal.