In this case, we have an iPhone 7 without loud speaker sound from our customer, customer has tested and discovered both ear speaker and microphone worked well, after hardware troubleshooting and replacing the charging dock assembly and loud speaker, the iPhone loud speaker still has no sound. The no sound loud speaker is therefore caused by motherboard defect. In this article, we will share with you how to fix iPhone 7 loud speaker no sound by motherboard repair, hope you enjoy our sharing.
Step 1. Function Test
Turn on the iPhone and test function. Play the ringtones through iPhone, but there’s no sound. Go to the Voice Memos and record, the recording has no sound either.
Step. 2 Diagnosis & Troubleshooting
Turn off the iPhone, and take out the motherboard. We should measure the diode resistance of the charging port connector pin 1,3,47,51, and the diode resistance of bonding pads.
As we troubleshooting, we first ruled out the charging port flex cable defect and loud speaker defect, then ruled out open or short circuit on charging port connector, and finally excluded bonding pads defect, hence we determine the reason caused the loud speaker no sound is loud speaker amplifier IC U3402 or M2800
Step 3. Repair
Add solder flux, then use the hot air gun and tweezers to install a new U3402
Step 4. Reassemble & Test
reassemble the motherboard and test. Ringtones play normally. Voice record works fine and recording plays normally. Case closed
Please refer to below detailed video:
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Tools and Materials Used in This Video:
- Solder flux
- Hot air gun
- PCB cleaner
- Cleanroom wipes
- Desoldeing braid/solder wick
- Rework station
- Knife blade
- iSclack suction pump