Maintenance of iPhone 7 is not booting after falling

After iPhone 7 fell down, the mobile phone no booting was replaced, the chip u2301 was replaced, and the two S5 Capacitor on the right of Baseband were removed, and the fault was repaired perfectly.

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

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

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

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.

402;IMG_260

Maintenance of iPhone 7 is not booting after falling down Figure 5.

After cutting off,Short circuit is no longer used. After installation test, the machine is started normally and the maintenance is finished.

449;IMG_261

Maintenance of iPhone 7 is not booting after falling down Figure 6.