iPhone 7 Plus Water Damage and Won’t Turn On

Phénomène de dysfonctionnement

Receive an iPhone 7 Plus water damage and won’t turn on.

After carefully checking the cosmetics. There is some corrosion around the WI-FI module, and the water-proof label was red.

Dépannage

First, clean the moldy area with PCB cleaner around WI-FI, then connect with the DC power supply, the current jumped to very high value.

Check the PP_BATT _VCC line and PP_VDD_MAIN line, both two lines are normal after checking the diode value.

When we checked the PP_VDD_BOOST line, the diode value was 0, which means this line was shorted.

There are so many components and chips on this line, so we have to find out which one was shorted.

Here we can use the rosin inspection method to find out the shorted component

First, coat some rosin smoke on the surface of those components and chips. 

Then use the multimeter needles to connect with the DC power supply, one needle connected with the positive side of the component and the other needle connected with the ground. And we set the output voltage at 3V.

Once get connected with the motherboard, we found the rosin on the capacitor C3002 was melted. 

Then replace the C3002 with a new one and measured the diode value on PP_VDD_BOOST again, the short was gone.

Assemble the phone and tested again, problem resolved.

Cours de réparation de la carte mère de l'iPhone 7