iPhone X Stuck On Apple Logo iTunes Error 4013

We have an iPhone X motherboard and two flex cables in the box. Here it writes: iPhone X Error 4013.

Check the motherboard first. Nothing goes wrong.

Let’s get the motherboard installed and check. Press the power button. The phone enters into recovery mode automatically.

Judging by this, the motherboard comes with restore failure and therefore the phone cannot enter into the system normally.

Let’s restore the phone and check whether it comes with error 4013.

Restore the phone with 3U Tools. The phone can be restored normally. What’s more, the phone can be normally activated after restore.

Go to Settings>General>About. We can check baseband info here.

We can confirm now that the motherboard is normal. The fault is probably related to other parts.

Get the earpiece speaker and sensor flex cable and front camera flex cable installed. Turn on the phone. The phone is stuck on Apple logo and keeps restarting.

Judging by this, the fault is related to the earpiece speaker and sensor flex cable or the front camera flex cable.

Disconnect the earpiece speaker and sensor flex cable. Press the power button to turn on the phone. The phone turns on normally.

We can confirm now that the fault is related to the earpiece speaker and sensor flex cable.

Check the earpiece speaker and sensor flex cable under the Microscope. The Flood illuminator module is mouldy.

Heat with Hot Air Gun to remove the Flood illuminator module. We can see that its bonding pad is severely corroded.

Clean the bonding pad thoroughly and solder the module back to the bonding pad.

Get the earpiece speaker and sensor flex cable installed and reassemble the phone.

The phone turns on normally.