After Apple Tablet iPad 2018 fell, the black screen did not turn on for repair.

After Apple Tablet iPad 2018 fell, the black screen did not turn on for repair.

After Apple’s flat-panel iPad 2018 fell, the black screen didn’t turn on. I immediately thought that the screen might be broken, or the motherboard was broken and the components were soldered. In this case, we must first rule out the screen problem.

Machine model: Apple Tablet iPad 2018

Fault phenomenon: Flat iPad 2018 fell to the ground, and when it was reused, it was found that the screen black screen could not be opened.

After Apple Tablet iPad 2018 fell, the black screen did not turn on. Maintenance Figure 1

Maintenance process:

Because the customer said that it would not be turned on after a fall, he immediately thought that the screen might be broken, or the motherboard was broken and the components were soldered. In this case, the problem of the screen should be ruled out first.

Plug the charger into the machine without charging current, which means that the machine can’t be turned on. It seems that there is something wrong with the motherboard. Disconnect the screen and connect the main board with electricity, so there is no leakage. After pressing the power-on key, it instantly jumps more than 1A current, indicating that there is a short circuit in the main board, which is generally a problem with the power supply output.

Poke the peripheral capacitance of the hard disk with a multimeter, and none of them are short-circuited. Generally, the high current is caused by a short circuit. Open Xinzhizhao software, compare the bitmap, pick up the multimeter again and poke the capacitor around the power supply, and poke the short circuit of PP3V3 power supply. Look at the bitmap and find that this power supply is output from the power supply and connected to the capacitor and WiFi chip.

After Apple Tablet iPad 2018 fell, the black screen did not turn on. Maintenance Figure 2

Smoked rosin on the line in the simplest, rude and practical way, and found that the corner of the WiFi chip was hot. After grinding it for a while, I found two capacitors on the corner inside the chip, and picked them up with a sharp knife.

After Apple Tablet iPad 2018 fell, the black screen did not turn on. Maintenance Figure 3

After Apple Tablet iPad 2018 fell, the black screen did not turn on. Maintenance Figure 4

After another dozen PP3V3 values are normal, the installation test shows that the tablet is turned on normally, WiFi can be turned on normally, the signal is normal, and then green oil insulation is applied, and the maintenance is over.