iPhone 6s can't read sim card for repair

iPhone 6s can’t read sim card for repair

Machine model: iPhone 6s
Malfunction: The sim card can’t be read by the phone card.

iPhone 6s can’t read sim card for repair figure 1.

Maintenance process:
Mobile phones can’t read sim cards, which are generally divided into two types:
1. signal receiving part.
2. Signal transmitting part.
This mobile phone and plug-in card display no serviecs, and the operator can be displayed in the settings, indicating that there is no problem in signal reception, so the fault is locked in the signal transmission part, which is sent from RF IC chip through 2G power amplifier chip and then ANT Switch chip.
During maintenance, the failure rate of 2 power amplifier damage is quite high. Replace the 2G power amplifier U2GPA_RF chip directly, and the fault remains the same. It seems that it is not the fault of 2G power amplifier. Replace the power amplifier IC U_WTR_RF chip, and the signal display is normal, and the call is normal. This is the end of the maintenance.
Therefore, it is concluded that the mobile phone can’t read the sim card due to the damage of RF IC U_WTR_RF chip.