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NO IMEI, NO Signal, NO Activation - PP_1V0_SMPS5 Low resistance

I have an iPhone 7 NO IMEI, NO Signal, NO Activation.

I have REMOVED BBPMU_RF chip and measured values in diode mode. I found out that Pad #87 which is PP_1V0_SMPS5 line. (See attached Image) The measured value is 0.053. The normal values according to ZXW Tool is 0.248

and Pad #99 which is PP_SWS_S5 the measured value is 0.043. The normal values according to ZXW Tool is 0.245

I have also checked

WHAT I DONE:

I have REPLACED BBPMU_RF chip with a new one but problem still exist.

I have checked visually all capacitors around BBPMU_RF chip (No damage all looks good)

I have measured all voltages around BBPMU_RF. All OK.

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Postado: 27 de mai de 2020

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On the Qualcomm boards this problem starts at the BBPMU from flexation we presume as it is closer to the flex line than the Intel boards which don’t suffer from this problem.

On the Qualcomm boards when the BBPMU IC fails it usually sends a higher voltage to the BBCPU which cannot handle it and develops a short.

I wouldn’t spend too much more time on this phone unless it has had the audio IC repaired which I would than remove and re-ball the BBCPU.

Don’t rely on the ZXW readings always compare to a known good board.

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I can not tell if the IC was repaired or not. I guess it has not been touched since There is no flux arund it or can not see any jumper....

28 de mai de 2020 por Peter Hupuczi

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iPhone 7

NO IMEI, NO Signal, NO Activation - PP_1V0_SMPS5 Low resistance

Update (05/28/2020)

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