H2 1. Two Root Causes of Full Screen Touch Loss
H3 1.1 Damaged Touch Digitizer
Cracked front glass breaks internal ITO touch circuits; replacing a fully tested digitizer will fully recover touch function.
H3 1.2 Mainboard Touch Power Circuit Defect
Damaged supply capacitors lead to abnormal touch voltage; new digitizer still fails after replacement and needs motherboard component maintenance.
H2 2 Stepwise Professional Fault Diagnosis Flow
- Swap verified qualified digitizer for test; touch recovery means original touch panel broken
- If touch still invalid, power on and test touch LDO voltage with multimeter
- Low abnormal voltage indicates faulty capacitors on logic board
H2 3 Disassembly Protection & Bulk Supply Standard
Do not overheat Face ID dot projector area to avoid permanent facial recognition failure; our factory’s Pro digitizers adopt anti-interference flex and high-strength glass with 100% full touch testing before delivery.