How to Fix iPhone 7 / 7 Plus iTunes 4013 Error

Have you ever gotten into iTunes error 4013 on iPhone 7/7 Plus? In fact, this is one of the most common problems for iPhone users. When restoring or downgrading iOS on iPhone, error codes usually appear. The iTunes error 4013 of iPhone 7/7 Plus is usually caused by fake welding or CPU damage. It may also be related to the power supply of the baseband PMU or NAND flash memory. In this article we will show you how to resolve this "Error 4013".

Fix the equipment needed for this case :

Rework Station

Electron Microscope

PCB Holder

Digital Multimeter

Malfunction Display :

First, press power button to power on, the phone gets stuck with iTunes Recovery Mode and has no access to the system. Next, connect it with computer and restore via iTunes, error 4013 appears during the restoring process. The phone restarts afterward.

Malfunction Analysis :

iTunes Error 4013 of iPhone 7/7 Plus is usually caused by pseudo soldering or damage of CPU. The problem might also be related to power supply of baseband PMU or NAND flash. Since CPU repair is quite difficult, to start with we can check power supply of baseband PMU and NAND flash.

Connect battery connector with Power Supplier, and press power button on the Power Supplier. The system will then detect power button press. The run voltage measurement of baseband PMU test points C5623 and C5631, the measured value of C5623 and C5631 are normal. Judging by this, power supply of baseband PMU is normal.

Malfunction Repair :

Let’s move to the power supply of NAND Flash, let’s remove black adhesive around NAND Flash with Hot Air Gun.

Then continue to measure voltage of NAND Flash test points C1701, C1721 and C1704. Judging by the measured value, power supply of NAND Flash is also normal.

Let’s try to replace the baseband PMU and see how it works. Detach baseband PMU from the board with hot air gun, then clean the bonding pad with resin-soaked Solder Wick.

Tips: some chips are sealed to the bonding pad with black adhesive, be careful with your operation to avoid knocking pads off the board.

Clean with PCB cleaner afterward.

Tools List Used :

Straight Tweezers

Paste Flux


Solder Wick

PCB Cleaner

Cutting Nipper

Anti-static Plastic Pry Bar

Soft Brush

Sculpture Knife

Apply some paste flux to the bonding pad, get a new baseband PMU in position(be careful with the direction). then solder with Soldering Rework Station.

Once done, wait for the logic board to cool for 5 minutes and clean thoroughly with PCB cleaner afterward.

Assemble and Test :

Till now, the whole repair process is fully finished, let’s get the logic board and display assembly installed. Connect the battery and press power button to power on, the phone gets stuck with iTunes Recovery Mode. We need to connect it with computer and restore via iTunes. The phone can be restored normally.

Once completed, the phone restarts automatically, fault cleared.

(NOTE: get the phone full assembled after confirmation of fault clearance.)

Now, iPhone 7 Plus error 4013 is perfectly fixed. For more information about iPhone 7 Plus mobile phone CPU repair methods, please visit

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