Ways to fix iPhone which cant be turned on WIFI

If your cellular data is running out, but your wifi can not be turned on and the Wi-Fi MAC address can be found in “about iPhone”. In this time, you will know how depressed you are and maybe your wonderful day will be ruined. So, how can we fix it? Vipprog can help you.

First teardown iPhone and then measure the diode data of Wi-Fi chip  and PCIE  bus communicating through CPU. The test point of PCIE bus is on the coupling capacitance that is on the right of U1501, as shown in picture 1-1.

 

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The Wi-Fi chip cannot be removed when the diode data of PCIE bus is being tested. Otherwise, the diode data to Wi-Fi can be infinite. The circuits between Wi-Fi solder pad and the 6 capacitances often disconnect. If that happens, measure the ends of capacitance. The normal diode data is about 350 on one end and 500 on the other end.

If the iPhone diode  data of the 6 capacitances is normal, then remove the Wi-Fi chip to measure the diode data of every pin of solder pad. If all the data is normal, first use a normal Wi-Fi chip to replace the old one and turn on iPhone to test. If the trouble is the s till the same, it is caused by unqualified Wi-Fi working condition.

After checking the function diagram, we find that the voltage of Wi-Fi clock is not measured. Remove the Wi-Fi and then measure the clock, there is not 0.9V voltage. The frequency of the Wi-Fi clock is 32.768kHz, which is made by the Y1200 crystal oscillator. Then Y1200 crystal oscillator transmits it to power chip . Power chip transmits it to Wi-Fi chip. Considering the iPhone is dropped, the crystal oscillator may be broken because it is not anti-shock. Replace the old Y1200 crystal oscillator. The Y1200 material object is shown in picture 1-2.

 

1-2

After the replacement, turn on iPhone and test. Wi-Fi switch can be turned on normally and Wi-Fi signal becomes normal. The trouble is removed. You can continue to enjoy your wonderful day.