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iPhone Wi-Fi circuit repairing

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This video mainly explains how to find the Wi-Fi circuit signals

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and measurement points of iPhone 12 Pro Max

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Search method step 1, find the Wi-Fi chip position number in the component map

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Step 2, search for the position number in the schematic diagram

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Step 3, find the corresponding signals according to the circuit diagram

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Step 4, jump to the bitmap to view the connected components,

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and we can measure the voltage and diode value at the yellow position in the bitmap

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When checking the maps, first open the component map, circuit diagram, and bitmap of the iPhone 12 Pro Max

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Find the Wi-Fi chip in the component map and confirm the position number,

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then search for the Wi-Fi position number in the schematic diagram

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After searching for the Wi-Fi chip, find the corresponding signals

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First find the main power supply of the Wi-Fi chip

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Pins 169, 183, and 205 of the Wi-Fi chip are the main power supply pins

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Jump to the bitmap, the main power supply will connect many chips

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This power supply is rarely damaged when repairign the Wi-Fi circuit

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Let's find the 1.8V and 1.2V power supply of the Wi-Fi chip

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Pins 5 and 6 of the Wi-Fi chip are the 1.8V power supplies

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Jump to the bitmap according to the name,

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the 1.8V power supply is connected to the main power supply through the middle connection point

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Pin 204 of the Wi-Fi chip is the 1.2V power supply

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Jump to the bitmap according to the name,

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the 1.2V power supply is also connected to the main power supply through the middle connection point

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Let's find the 32KHz clock signal of the Wi-Fi chip

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Pin 145 of the Wi-Fi chip is a 32KHz clock signal

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Jump to the bitmap according to the name,

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the clock signal is connected to the main power supply through the middle connection point

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Let's find the power supply of 0.72V and 1.02V generated by the Wi-Fi

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The pins 186 and 200 of the Wi-Fi chip are 1.02V power supply pins

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Jump to the bitmap according to the name,

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the 1.02V power supply is connected to the inductor L253_W,

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and it is connected to the capacitor C254_W

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Returns to the inside of the chip after passing through the capacitor

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The pins 184 and 198 of the Wi-Fi chip are the 0.72V power supply

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Jump to the bitmap according to the name,

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the 0.72V power supply passes through the inductor L255_W

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and then connects to the capacitor C256_W

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Returns to the inside of the chip after passing through the capacitor

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Let's find the open signal of the Wi-Fi chip

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Pin 174 of the Wi-Fi chip is the open signal

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Jump to the bitmap according to the name,

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and the open signal is connected to the main power supply through the middle connection point

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Let's find the PCIE bus

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The PCIE bus has a total of 8 lines

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Pin 44 of the Wi-Fi chip is the PCIE bus reset

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Jump to the bitmap according to the name,

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and the bus reset is connected to the CPU through the middle connection point

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Pin 86 of the Wi-Fi chip is the PCIE bus clock request signal

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Jump to the bitmap according to the name,

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this signal is connected to the CPU through the middle connection point

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Pins 29, 15, 71, and 57 of the Wi-Fi chip are PCIE bus data pins

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When the data bus is connected to the CPU,

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it will pass through the coupling capacitor

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Pin 29 , jump to the bitmap according to the name,

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pin 29 is connected to the CPU after passing through the coupling capacitor C1112

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Pin 15, jump to the bitmap according to the name,

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pin 15 is connected to the CPU after passing through the coupling capacitor C1113

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Pin 71, jump to the bitmap according to the name,

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pin 71 is connected to the CPU after passing through the coupling capacitor C2710

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Pin 57, jump to the bitmap according to the name,

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pin 57 is connected to the CPU after passing through the coupling capacitor C2711

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If one of these coupling capacitors is damaged or missing,

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Wi-Fi cannot be turned on

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Pins 113 and 99 of the Wi-Fi chip are PCIE bus reference clocks

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Pin 113, jump to the bitmap according to the name,

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the clock signal is directly connected to the CPU

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Pin 99, jump to the bitmap according to the name,

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the clock signal is connected to the CPU through the middle connection point

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Let's find the test bus from the CPU to the Wi-Fi chip

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Pin 74 of the Wi-Fi chip is the test bus input, named TDI

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Jump to the bitmap according to the name,

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and the input signal is connected to the CPU through the middle connection point

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Pin 60 of the Wi-Fi chip is the data output of the test bus, named TDO

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Jump to the bitmap according to the name,

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the output signal is connected to the CPU through the middle connection point

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In this way, we have searched for all the signals of the main working conditions of the Wi-Fi chip

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If Wi-Fi cannot be turned on, we need to measure the working conditions of the Wi-Fi

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Ok, that's all for this video