Malfunction Phenomenon
The phone can’t receive sounds when we make phone calls.
Trouble Shooting
iPhone X No Sound issues, it might be caused by the
First, take apart the phone and run the cosmetic inspection of the motherboard, to see if there is any abnormal like corrosion, pads missing, etc.
Then we can separate the upper layer from the lower layer. After that, we found there are some CPU cooling gel on cylinders around the edge of the lower layer which causes the upper layer to be disconnected from the lower layer.
Check the schematics, the rails are related to the I2S signals.
So we clean the cooling gel on the cylinders around the edge of the lower layer with PCB cleaner. then make the two layers resolder together. After that, assemble it and test again, the problem resolved.
iPhone X Motherboard Repair Course
Tips: Most of the issues for the double-layer motherboard like the iPhone X are caused by the poor connection between the two layers of the motherboard.
So it’s an essential skill that needs to be handled expertly to disassemble and recombine the two layers of the motherboard.
