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.
1-1
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.
1-2
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.
1-3
1-4
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.
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