Fix SIM card no service after iPhone 6s drop into water

Have you ever met the iPhone 6s into the water and then had no service even though you dry the water. At this time ,the iPhone 6s can not be used to communicate with people, this is frustrating. So, what should we do to fix it? Viprog tells you.

First, Enter system to test and iPhone displays no service with SIM card . In “settings” we can see operator options but no service. That the operator options shows suggests trouble does not in signal reception circuit but in signal emission circuit. After teardown, we find the motherboard ,has been watered and corroded, as shown in picture 1-1.

 

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Second, clean the corroded places and test the power supply of each chip. We find the power supply diode data of 2G amplifier chip is infinite. After checking the circuitdiagram, we know the power starts from PP_VCC_MAIN and then pass insurance resistance R4501_RF to 2G amplifier at last, as shown in picture 1-2 and The location of resistance R4501_RF in PCB bitmap is shown in picture 1-3.

 

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Then, Assemble the resistance R4501_RF and enter system to test. The trouble is still the same. Use a 10cm jump wire acting as a phantom antenna to check where is damaged exactly. The enameled wire starts from the 2G emission chip of RF chip, as shown in picture 1-4.

 

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Finally, after the above steps, enter system to test and iPhone still displays no emission signal. We can conclude the RF chip is broken. Replace RF chip and the trouble is removed.

Resolved: iPhone 6P no IMEI when dialing *#06# and display is searching

Do you have met iPhone 6 Plus displays no IMEI when dialing *#06#. There is baseband firmware in “about iPhone” and iPhone keeps displaying “is searching ”. So, why is that? Vipprog answer for you.

First assemble it to testing iPhone assembly and test. After power on, iPhone will display “no SIM card ” without inserting SIM card. If that happens, there is modem firmware in “about iPhone”(picture 1-1). That is to say, there is baseband.

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Then, numbers on the back of modem firmware suggests there is baseband CPU. There is not baseband, if without numbers. Input*#06# on the dial interface without inserting SIM card. If it is normal, the same IMEI in “about iPhone” will show up. If there is no response and IMEI after inputting*#06#, in addition, there is baseband firmware, so the problem cannot be caused by baseband. Displaying no IMEI after dialing *#06# is often caused by the two RFFE bus of baseband. There are four test points under NAND Flash , as shown in picture 1-2.

 

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Furthermore, the four test points do not reveal any copper. Therefore, we need to use a pointed probe Multimeter  to measure or scrape them. The normal diode data is between 300-400. But the RFFE2_CLK (picture 1-3) diode data is 750 which is seriously high. It is clear that RFFE2_CLK signal antenna is not normal. The diode data 750 comes from CPU. So the circuit breakage of baseband solder pad has been excluded. The normal diode data is about 400. The diode data of RFFE2 is from the DSM amplifier, and it probably caused by DSM amplifier’s U_DSM_RF pseudo soldering. The material object of DSM amplifier IC is shown in picture 1-4.

 

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Last, reassemble DSM amplifier and measure the diode data of RFFE_CLK. Now the data is 380 that is normal. After power on, iPhone shows IMEI when dialing *#06#. Insert SIM card and the signal becomes normal, even for several days. Congratulation, the trouble is removed and your iPhone back to normal.

Repair WIFI too weak to connect on iPhone6

Now your iPhone 6 wifi signal is weak and can not connect wifi, sometimes it could connect but can't use. The Wi-Fi chip has been replaced. You will certainly ask why. Vipprog answer for you.

After power on and test, signal cannot be searched with Wi-Fi switched on. After teardown the iPhone by new Screwdriveropening tool Set , we find the connection between the iron sheet and the Wi-Fi antenna is not doing well, as shown in picture 1-1.

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Wi-Fi signal can be searched with the well connection between the iron sheet and the Wi-Fi antenna . But the Wi-Fi signal is not stable because customer has already replaced the Wi-Fi chip . First excluding the problems caused by Wi-Fi chip, we mainly measure Wi-Fi signal reception circuit.

After measuring, we know capacitance C5133_RF is short circuit. The location of C5133_RF is shown in picture 1-2 and in material object picture 1-3.

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After replacing a new capacitance, turn on iPhone and test. The Wi-Fi signal keeps stable. Your iPhone problem is been solved.

Ways to fix iPhone which can't 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 still 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.

 

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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.

How to repair iPhone 6 display no service and no IMEI when dialing "*#06#"

Do you feel curious why the iPhone 6 will not be able to display IMEI when dialing "*#06#" after falling down? But have to be aware of is "about phone" can shows it. So, what's wrong with your iPhone? Vipprog answer for you.

First you have to know where the problem is. This kind of trouble is caused by RFFE bus of the baseband that does not work. In most cases of dropped iPhones, the circuit of pin U1 of the baseband CPU is disconnected. The location of pin U1 is shown in picture 1-1.

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To solve the problem that dropped iPhone displays no IMEI when dialing *#06#, first remove basebandCPU to check whether the pin U1 comes off from the solder pad. Then measure the iphone diode  data of U1, U2, U5 and R5.

After teardown iPhone, remove baseband CPU, we can find pin U1 and pin V1 come off from the solder pad, as shown in picture 1-2. This iPhone shows no IMEI when dialing *#06# because when pin U1 comes off, baseband CPU cannot communicate with peripheral circuit.

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Above all scrape the circuit that is connected to the pin U1 and V1 on solder pad, as shown in picture 1-3.

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Then plate the welded joints of U1 and V1 with tin and place two enameled jump wire on the solder pad of U1 and V1, as shown in picture 1-4.

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At last, paint green UV Solder Resist on them and reassemble baseband CPU. The signal becomes normal after power on, so the trouble is removed. You can normal use the iPhone again.