Iphone 7 No Service and does not recognize Simm.

[Buzz]

Hello everyone I am a new member and a novice at this field but have learned a lot from many of you.just watching, reading.

I recently received this iphone 7 from my grandson who had taken it to Apple for Boot Loop. They told him he needed to purchase a new phone. He said it had never been repaired or water damaged. Opened and inspected with microscope found no visual problems. After reassembling and doing nothing to the phone it would boot up and restore on itunes but would not activate. Error was that it could not recognize Simm card. Tried a known working card but same results.

Tested current draw of phone and it would charge but slowly. max amps .80 but would constantly fluctuate 0 to.80
I have removed board and tested amp draw. 0.0 powered off and fluctuates from .03 to .80 when turned on.
Checked for hot spots with infrared and found that the IC power supply chip 338S00225-A1 appears to be warmer than any component on the board but only by about 10 to 12 degrees F.. Unfortunately I do not have a known good board for comparison.

I am new to this and would appreciate any suggestions. I have ordered ZXW and should be here soon.

Thanks

[Jessa_the_Professa]

iPhones that do not have water damage often have "signature failures" so that is where we want to start. Is there a signature failure for iPhone 7 searching no service? Yes. For any qualcomm iPhone 7 (the A1660 model) the common problem is a failure of the baseband pmu from board flexion that progresses to failure of the qualcomm baseband CPU via an internal short circuit. Before iOS12, this problem would manifest as a short 10-15 second boot loop because baseband function was required for boot. Then (likely because of this overwhelmingly common problem) iOS 12 no longer requires baseband function so these phones can now boot, but of course will not get cell service since they have no baseband function. For a phone that is not restored, i.e. a phone that is updated and already activated, then the phone will show "searching no service" with a characteristic triangle with exclamation sign--caution symbol. We don't get that clue with a phone that has been restored, but the "can't activate" is very consistent with the same problem.

The bad news is that if the phone actually has an internal short circuit within the baseband CPU, then that chip can not be replaced since it is unique to the device. The good news is that all A1660 phone are under recall for this problem--as long as you put all original parts on the phone.

[Buzz]

Thanks Jessa..I will take the phone to Apple and see what they have to say.

[Buzz]

Update: I took the iphone 7 in for the recall today. They said they were happy to repair the board under the recall BUT...it had a non OEM screen on it (which I had recently replaced)and it would have to be replaced with OEM before they would accept it for the recall. (149.00). I had the them install the new screen.

I asked if I would get my old screen back and they refused to return it (company policy). Just thought I would share my experience. Thanks again.

[Jessa_the_Professa]

Yes, this is why I specifically warned you above...
AS LONG AS YOU PUT ALL ORIGINAL PARTS ON THE PHONE.

This is not an unreasonable policy—when you turn in the phone they will reuse the lcd. They can’t refurbish an aftermarket lcd so that value they are getting is less of you have taken their oem lcd and already refurbished it yourself.
Of course the value of a cracked oem ip7 lcd is about $25, so it is a shame to have to pay them retail for a screen.