Solution speaker and handset no sound failure repair
Here I will explain about different reasons of why there is no sound in mobile phone and how to fix this problem.
Redmi speaker has no sound when playing the music, and the handset also has no sound when make the phone calls. We need to repair it.
First check whether the Redmi is in headphones mode, after checking, the Redmi doesn't in headphones mode, but the speaker and handset still not working.
Disassemble the Xiaomi Redmi by phone opening tools, use digital multimeter to measure the EAR_DET voltage, after measurement, there is no voltage and it is short circuit， R1904 is short circuit.
Take out the R1904 by Precision Titanium Alloy Tweezers, we find the capacitor DCD_HS_DET is short circuit.
Picture 18-12-1
Check Redmi schematic diagram, we know that CDC_HS_DET leads to a Redmi power supply IC. Test the Redmi, we find the power supply IC is overheat, replace the new Redmi power supply IC.
Now find a 2.2K (222 capacitor), and then replace the R1904 capacitor, use QUICK 861DW hot air rework station to solder it with jump wire.
Picture 18-12-2
Soldering the Redmi power supply IC, and then turn on Redmi to test, EAR_DET headphone detection voltage 1.8V is normal, Disconnect the power, and then install the Redmi, after testing, the headphone speaker and handset all works properly, the repairs end!
Redmi speaker has no sound when playing the music, and the handset also has no sound when make the phone calls. We need to repair it.
First check whether the Redmi is in headphones mode, after checking, the Redmi doesn't in headphones mode, but the speaker and handset still not working.
Disassemble the Xiaomi Redmi by phone opening tools, use digital multimeter to measure the EAR_DET voltage, after measurement, there is no voltage and it is short circuit， R1904 is short circuit.
Take out the R1904 by Precision Titanium Alloy Tweezers, we find the capacitor DCD_HS_DET is short circuit.
Picture 18-12-1
Check Redmi schematic diagram, we know that CDC_HS_DET leads to a Redmi power supply IC. Test the Redmi, we find the power supply IC is overheat, replace the new Redmi power supply IC.
Now find a 2.2K (222 capacitor), and then replace the R1904 capacitor, use QUICK 861DW hot air rework station to solder it with jump wire.
Picture 18-12-2
Soldering the Redmi power supply IC, and then turn on Redmi to test, EAR_DET headphone detection voltage 1.8V is normal, Disconnect the power, and then install the Redmi, after testing, the headphone speaker and handset all works properly, the repairs end!
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