The iPhone 13 Pro Max is a highly sought-after high-end smartphone, but due to its sophisticated hardware and software system, it is also susceptible to various malfunctions. For some users, the sudden inability to power on their iPhone 13 Pro Max is a common but frustrating problem. This article from Phonefix will detail how to troubleshoot and repair an iPhone 13 Pro Max that won't turn on, using a real-world repair case, including common diagnostic steps, tools used, the repair process, and solutions.
I. Problem Description
【Model】 iPhone 13 Pro Max;
【Customer Description】A customer reported that their iPhone 13 Pro Max had previously been repaired at an authorized service center due to water damage, and the phone worked normally afterward. However, recently the phone suddenly stopped turning on and wouldn't charge. The customer stated that the device was out of warranty, and Apple's official repair costs were too high, so they chose to bring the phone to our service center for repair.
II. Repair Procedures
1. Initial Inspection and Power Test
Upon receiving the customer's iPhone, first perform a visual inspection and attempt to press the power button, but the device does not respond. For this type of power-on failure, the first step in repair is usually a power test to quickly pinpoint the approximate location of the fault.
Tools:
· DC power supply (regulated power supply);
· Precision screwdriver;
· Suction cup tool;
Steps:
· Power off: Ensure the iPhone is completely powered off;
· Disassembly: Use a precision screwdriver to remove the screws on the bottom of the device, and gently open the phone screen using a suction cup tool. Be careful during disassembly to avoid damaging the ribbon cables and battery connections;
· Connect the adjustable power supply: Provide power to the motherboard through the regulated power supply and monitor changes in current and voltage. If the current data is unstable or excessive, it may indicate a short circuit on the motherboard.
Note: If the device displays abnormal current data during testing, the fault may be on the motherboard.
2. Motherboard Diagnosis and Disassembly
Next, we need to further analyze the iPhone 13 Pro Max's motherboard to check for short circuits or other hardware failures.
Tools:
· Soldering iron;
· Rosin;
· Atomizing pen;
· Precision screwdriver;
· Stereo microscope;
· Motherboard disassembly tools;
Steps:
· Layered Motherboard: Remove the motherboard from the phone body and carefully inspect each part. To more accurately locate the problem, we disassemble the motherboard layer by layer, observing the current data in each area.
· Current Testing: We used an adjustable power supply to connect the motherboard for testing and found that the current data of the upper layer of the motherboard was significantly abnormal, indicating a short circuit problem in the upper layer.
· Treating the Motherboard with Rosin Solder Paste and Atomizing Pen: To further repair the short circuit problem, we used an atomizing pen to apply a layer of rosin to the motherboard and heated it to ensure even coverage. Rosin helps clean the circuit board and eliminate short circuits. Then, we inspected the treated area under a stereo microscope.
• Check USB Chip Heating: By touching the motherboard, we found that the USB power management chip was slightly warm during use, which usually indicates a chip malfunction. The malfunction may be due to an internal short circuit, causing unstable current.
3. Replace the Damaged USB Chip
Based on our analysis of the motherboard, we determined that a damaged USB power management chip was the main cause of the inability to power on. To fix this problem, we need to replace the USB chip.
Tools:
• Soldering tools (soldering iron);
• Motherboard disassembly tools;
• Precision tweezers;
• iPhone USB chip (new part);
Steps:
• Remove the old USB chip: Use a soldering iron to heat the old USB power management chip and easily remove it from the motherboard. Be extremely careful during removal to avoid damaging other components on the motherboard.
• Clean the circuit board: Gently wipe the motherboard surface with a lint-free cloth, ensuring there are no solder residues or rosin particles.
• Install the new chip: Place the new USB power management chip on the motherboard and solder it using a soldering iron tips. Ensure a secure and reliable connection between the chip and the motherboard during soldering.
• Testing the Repair Effect: After installing the new chip, we reconnected the adjustable power supply for testing, confirming that the current data had returned to normal.
4. Assembly and Final Testing
Having completed the above repair process, we have fixed the hardware issue on the iPhone 13 Pro Max. Next, we assemble the device and conduct final functional tests.
Tools:
• Precision screwdriver;
• iPhone screen fixing tool;
Steps:
• Reassemble the Device: Reassemble the motherboard and other iPhone components (such as the battery, screen, etc.), and tighten all screws using a precision screwdriver.
• Connect to Power and Power On: Connect the device to the charger and try pressing the power button. At this point, the iPhone 13 Pro Max can successfully power on and enter the system, confirming a successful repair.
• Perform Full Functional Testing: We conducted a full functional test on the repaired phone, including charging, touchscreen operation, camera, audio, etc., to ensure all functions are working properly.
After the detailed troubleshooting and repair process described above, the iPhone 13 Pro Max has successfully returned to normal operation. The device can not only power on normally but also successfully enter the system and charge. The fault was perfectly fixed and the customer's iPhone returned to full functionality.
A number of factors, from straightforward battery issues to intricate motherboard malfunctions, might cause an iPhone 13 Pro Max to not switch on. We advise getting your own phone repair tools from China Phonefix if you intend to fix it yourself. This will guarantee that you employ top-notch professional tools, increasing the effectiveness and success rate of repairs. With the help of this instruction, we hope you can fix the power-on issue with your device and resume regular use.
