iPhone 12 Pro Max Black Screen and Power-On Failure: Repair Guide

Device Model: Apple iPhone 12 Pro Max

Symptoms:

• The customer reported that their iPhone 12 Pro Max Screen suddenly went black and wouldn't turn on.
• Despite charging the phone and attempting a forced restart, there was no response.
• Connecting the iPhone to a computer also yielded no results.
• The customer urgently needed access to important work data and had previously visited a local repair shop without success.
  
  

Repair Process

1. Power-On Test

   • Conducted a power-on test by AiXun P3208 Power Supply, which revealed no signs of activity.
   • As the customer had already determined it was a motherboard issue, proceeded with the disassembly.
     
     

2. Disassembly

   • Removed the screen and battery.
   • Noticed that the motherboard's shielding had been removed and there were traces of prior repair attempts.

3. Layer Separation

   • Placed the motherboard on a iRepair MS1 preheating platform to separate the layers.
     
     
   • During this process, the CPU detached from the motherboard.
   • It was apparent that the CPU had been reattached using low-temperature solder, indicating the need for a reballing procedure.

4. Reballing and Repair

   • Completed the reballing procedure for the CPU.
   • Conducted a power-on test after the repair.
     
     

Result

• After reballing the CPU and completing the repair, the iPhone successfully booted up.
• All functions were fully restored.

If your iPhone, such as the iPhone 12 Pro Max, experiences a sudden black screen and fails to power on, try a restart first.

If the issue persists and the phone remains unresponsive even after charging, it is likely a hardware problem. We recommend seeking assistance from a reputable third-party repair shop or contacting the official customer support for further evaluation and repair.

China Phonefix offers all of the above cell phone repair tools, along with a comprehensive selection of iPhone repair tools, hardware, and iPhone accessories.