iPhone 7 does not read SIM card and does not charge for repair

Machine model: iPhone 7

Malfunction: No signal no serviecs, mobile phone does not read SIM card, and does not charge.

iPhone 7 does not read SIM card and does not charge for repair Figure 1.

Maintenance process: check that other functions are normal, remove the two screws to remove the screen, and take out the motherboard to check the Previously repaired machine.

iPhone 7 does not read SIM card and does not charge for repair Figure 2.

Cut the card slot with pliers, cut it open, slowly remove it, and drag it with normal temperature tin, leaving some tin. Look for Parts motherboard with Nand removed. When removing SIM card holder, put it upside down.SMD REWORK STATION 400 wind speed blows the back of the card holder at 50, and heat it evenly for about 10 seconds. Gently remove or so with tweezers. The card holder is perfect.

Put it directly on the board and add Flux, Cyclone 320, 3rd gear wind speed. After installation, insert the test card with 4G network and dial 10086.
If you can’t fix it now, just look for the charging chip, USB VCC 5V, standby VCC 1.8V,USB charging detection, main VCC,VCC startup, charging step-down output, battery VCC detection, charging drive signal and CPU power detection signal, all of which should be tested one by one.

Looking for Parts motherboard to remove one and install it. After testing, it still doesn’t charge, so USB management chip is also replaced.