1. Two Main Causes of Complete Touch Failure
The first cause is physical damage to the digitizer. Cracked front glass will break internal touch circuits, leading to total unresponsiveness. The second cause is defective capacitors on the mainboard. Abnormal touch power supply voltage will make a brand-new digitizer fail to work. Use a multimeter to test voltage for accurate judgment.

2. Professional Diagnostic Process
Replace with a tested good digitizer first. If touch recovers, the original digitizer is faulty. If the problem remains, check the mainboard power circuit and replace damaged components. This method avoids unnecessary part replacement and saves repair costs for technicians.
3. Disassembly & Wholesale Part Standards
Do not overheat the Face ID area during heating, or the facial recognition function will be damaged permanently. For Pro series wholesale parts, select high-strength glass and anti-interference flex cables. Strict factory testing for no dead pixels and stable touch is required for high-end device maintenance.
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