The SIM card of iPhone 6s cannot be read and repaired

Machine model: iPhone 6s
Malfunction: The SIM card of the mobile phone can’t be read.
Maintenance process: the test found that the card was not inserted, and the card holder was pressed and the invalid SIM card was prompted. Clean the card holder first, and the card insertion test is still invalid. Open Xinzhizao Soft drawing, here is a 6S SIM card drawing.

The SIM card of iPhone 6s cannot be read and repaired Figure 1.

If you don’t read the card, first check the card insertion detection pin of the card holder. There are more than 500 pairs of diode value, which are basically normal. Insert the empty card slot, and then measure the card to detect that pin VCC has 1.79V normal.

The SIM card of iPhone 6s cannot be read and repaired Figure 2.

The ground diode value of the six pin of the measuring fixture is normal.

The SIM card of iPhone 6s cannot be read and repaired Figure 3.

Measure the moment when the card holder is inserted according to the drawing of Xinzhizao Soft, and the card holder 1 pin VCC PP_UIM1_LDO11, which is supplied by Baseband power supply, is normally 1.8V When measuring, use an empty card slot to insert it, and immediately measure that there is no VCC.

The SIM card of iPhone 6s cannot be read and repaired Figure 4.

By the way, the 7 pin of the booth was measured, and there was no VCC.

The SIM card of iPhone 6s cannot be read and repaired Figure 5.

It is fully explained that the reason why the Baseband power supply does not output VCC to the card holder is that it does not read the card. Disassemble the whole motherboard, and first perform Baseband on Baseband power supply.Baseband can’t be turned on, then change the power supply of Baseband, and then test the plug-in card to recognize the card.