Apple iPhone XS MAX has no baseband

Apple iPhone XS MAX has no baseband.

This machine is a second repair machine, and the fault is that there is no baseband. After the initial overhaul, the CPU has traces of maintenance, and it flies directly. The specific maintenance process is as follows:

“Machine model” Apple iPhone XS MAX

[Fault phenomenon] No baseband

[Maintenance process] I received a XS MAS sent by my colleague for repair. My colleague said that it had no baseband. I had it repaired by someone before, so I sent it here to see if it was possible to repair it.

Apple iPhone XS MAX without baseband Figure 1

Apple iPhone XS MAX without baseband Figure 2

There is no baseband and it has been repaired, so it is more troublesome to repair it. The baseband of iPhone Xs Max is on the lower motherboard, and it can be repaired if the baseband CPU and baseband chips are not damaged.

So let’s look at it in layers first, and separate the upper and lower layers. At a glance, we can see that the baseband CPU has been touched and has been redone. First, hit the point where the baseband CPU passes through the middle frame to see if there is any virtual welding at home. In the process of typing, we find that the reset signal resistance from the power supply to the baseband power supply is OL. Look.blue print It is found that this reset signal is sent from the middle frame to the inside of the baseband power supply through a capacitor, and it can be known that the middle frame is disconnected by the value.

Apple iPhone XS MAX without baseband Figure 3

Apple iPhone XS MAX without baseband Figure 4

Directly pull the flying line to the lower layer, then directly attach it, and then brush it to see that the brush has passed through the baseband. After reactivation, the serial number will come out, and the baseband will return to normal, and the phone call will be normal.

Apple iPhone XS MAX without baseband Figure 5

Apple iPhone XS MAX without baseband Figure 6

[Maintenance Result] Install the motherboard into the.mobile phoneIn the power-on test, the mobile phone is turned on into the system normally, and the functions of charging, WiFi, sound, compass, vibration, telephone and so on are normal. The maintenance is over here.