HUAWEI Mate 30 Crack into Halves Damage Repair

HUAWEI Mate 30 Crack into Halves! Whether this phone can be fixed or not?

Modèle : HUAWEI Mate 30

Annoncé : 2019, September

Commentaires des clients

The client was drunk and break the phone into halves in an unconscious state.  And when woke up the next morning, only the upper half (with the motherboard inside) of the phone can be found. 

Seems it’s not the first phone issue caused by the drunk client.

Dépannage

No matter why and how the phone gets damaged like this, let’s have a check the motherboard first.

Remove the screws and take out the motherboard

The motherboard looks good, no obvious deform or damage

Connect the motherboard with the DC power supply, trigger to boot

The boot current jumped from 100mA to 40mA and was then fixed at 40mA

This defect phenomenon with a high chance is caused by the CPU power supply or the CPU dos not work.

Processus de réparation

Remove the shielding cover on the CPU chip and check carefully, the CPU looks fine.

Touch the small inductors around the CPU chip with the tweezers slightly to check. After checking, there is no component loose or missing.

Check the other side of the motherboard. The shielding cover on the PMU IC has gotten deformed, let’s remove the shielding cover and have a check

PMU IC looks good and the small components around it are also in the good conditions

A small inductor is loose and easy to be removed when pushing with the tweezer

However, based on the repair experience, the small inductor missing won’t cause 40mA no boot issue.

Anyway, let’s solder it back to position first.

After soldering back the small inductor and testing again, the issue is still the same (boot current fixed at 40mA).

Will the issue be caused by the CPU power supply? Let’s connect the DC power supply and measure the voltage values.

All the voltage values are OK.

So the issue might be caused by the poor connection of the two layers of the motherboard or the CPU.

Let’s resolder the CPU to have a try first.

• Remove the thermal grease on the CPU and black glue around the CPU
• Heat up and remove the upper RAM layer first
• Then remove the lower Kirin 990 layer CPU

After removing the CPU, there are some pad corrosive traces, so we’ll need to clean the glue and tins on the PCB pads.

Then measure the voltage value of the motherboard again, it shows the current is 5mA. This means the motherboard is fine.

Reball and solder the CPU chips back to the motherboard.

Then power on to test again, this time the boot current is normal, the phone can be booted normally.

The motherboard is fixed, and then let’s assemble the board to have a test

With the new screen, new battery, new housing cover, and the other new parts assembled, the Mate 30 can be booted normally, and test the functions, display, touch, audio, Wi-Fi, etc. are all OK.

The issue gets resolved perfectly by CPU resoldering.

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