Maintenance of iPhone 7 is not booting after falling

Machine model: iPhone 7

Description fault: doesn’t turn on after falling

Maintenance of iPhone 7 is not booting after falling down Figure 1.

Maintenance process: power on to see the current of the machine large current,The rosin smoke method power on found a Capacitor first melted.

Maintenance of iPhone 7 is not booting after falling down Figure 2.

After cutting off, it was still Short circuit, and it was found that u2301 was melted.

Maintenance of iPhone 7 is not booting after falling down Figure 3.

After removing it,Short circuit is still used, but it can’t be burned out with DC power supply, so you can only use Current heating test battery (Current heating test battery with too much current will easily burn PCB layer).

Maintenance of iPhone 7 is not booting after falling down Figure 4.

When the Current heating test battery was burned out, it was found that it was directly burned out. After removing it, it was no longer Short circuit. After installing u2301, it was found that Stuck on Apple logo was started and restarted. According to previous experience, it was suspected that there was something wrong with Baseband.

The VCC diode value near the Baseband power supply found that Baseband S5 VCC Short circuit. According to experience, it is suspected that there is something wrong with the Capacitor of the two S5 on the far right of Baseband.