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2.1.2. Signal Flow of the RF Receiving Part 

2.1.3.1.  Receiving Path Components 

Receiving path is shown in the following figure:   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Summary of Contents for Life Pure

Page 1: ...Page 1 of 22 BLU Life Pure Service Manual ...

Page 2: ...onents 8 2 2 Baseband part 10 2 2 1 Block diagram of the Baseband part 10 2 2 2 Power Management 11 2 2 3 Audio Section 12 2 2 3 1 Audio Codec Circuit 12 2 2 3 2 MIC Receiver Loop 13 2 2 3 3 Headset Loop 14 2 2 4 Baseband Fault issues 15 2 2 4 1 Analysis of the keyboard fault 16 2 2 4 2 Analysis of Display module circuit 17 2 2 4 3 FM Module 17 2 2 4 4 Camera Module 18 2 2 4 5 IO Interface 19 2 2 ...

Page 3: ...I2U000MA B800 TP IC GT915 Peripheral Configuration LCD 5 0 Backlight driver LM3630 CAMERA 13million pixel Memory card NA Antenna monopole Basic Performance Indicators Leakage current 90uA Standby current 7mA Call current as maximum power TBD Board level power GSM 32 5dBm DCS 29 5dbm Board level receiver sensitivity GSM 108dbm DCS 109dbm TRP GSM 27dbm DCS 25dbm Band1 23dbm Band8 22dbm TIS GSM 103db...

Page 4: ...Page 4 of 22 System Block Diagram CPU MT6589 PMIC MT6320 BATTRY CAMERA FM BT WiFi GPS LCD CTP KEYPAD MEMORY MT6167 SKY77590 YD165 SPK HP REC single SIM CARD MIC ...

Page 5: ...of 22 1 2 Motherboard Components Distribution 2 Signal Flow and Fault Analysis 2 1 RF Part 2 1 1 Block Diagram of the RF Section RF Block Diagram A N T PA Ant Switch SKY7759 0 Transceiver MT6167 CPU MT6589 GGG ...

Page 6: ...Page 6 of 22 2 1 2 Signal flow of the RF Transmitting Part 2 1 2 1 Transmitting Path ...

Page 7: ...eck Transceiver to see if IQ signals exist Check the PA output to see if there is RF signal in the path Y Check CPU N Check RF coaxial switch or matching network Y Check the Transceiver to see if there is RF signal output N VBAT PA_EN BAN DSW_DCS VAPC 是否 OK Replace PA Y Check CPU Y Check Transceiver if LE SCLK SDAT RFVCOEN VCXOEN have the correct signal N N N N Y Replace Transceiver ...

Page 8: ...Page 8 of 22 2 1 2 Signal Flow of the RF Receiving Part 2 1 3 1 Receiving Path Components Receiving path is shown in the following figure ...

Page 9: ...nsceiver has IQ Check CPU Y Transceiver has received signal 号 N Transceiver SDATA SCLK LE CXOEN are correct Y Check CPU N Whether the voltage of the transceiver is normal Whether 26MHZ is normal 正常 Y Check the corresponding power supply and 26MHZ resulting circuit N Replace transceiver Y PA has received signal N Check to see if there has signal in the matching circuit between PA and ANT N Check to...

Page 10: ...Page 10 of 22 2 2 Baseband part 2 2 1 Block diagram of the Baseband part CPU MT6589 PMIC MT6320 BATTRY CAMERA FM BT WiFi GPS LCD CTP KEYPAD MEMORY MT6167 SKY77590 YD165 SPK HP REC SINGLE SIM CARD MIC ...

Page 11: ...Page 11 of 22 2 2 2 Power Management The power management module is PMU IC MT6320 2 2 2 1 Mobile power supply system DC DC LDO ...

Page 12: ...ge 12 of 22 2 2 3 Audio Section 2 2 3 1 Audio Codec Circuit This phone applies YD165 which is a class D and non crack noise YAMAHA amplifier to drive speaker Block diagram of the audio system is as below ...

Page 13: ... 0 1V When MIC is in good condition but loop MIC has no echo then you need to check the basic bias voltage signal of the MICBIASP and MICBIASSP the language signals of the RECEIVER and MIC also need to be checked Receiver loop is simple The output of BB drive Receiver directly through Filter and ESD protected network as shown below ...

Page 14: ...es two signals Headset speaker and MIC If the headset fitting were in good condition when the headset plug in it appears abnormal such as The Headset speaker has no sound the MIC is invalid All this need to check the access conditions of the circuit above ...

Page 15: ...ices between the system connector and the CPU NO Connect the download cable then observe the Ammeter to see if it shows high current The normal current generally about 30mA Yes Quickly disconnect the connection and gently touch the chip to see if it is hot If not then focus point using the multi meter to measure the short circuit Yes Check the power manager and open the LDO to see if the voltage s...

Page 16: ... short circuit the equivalent of a long pressing this button At this point you should analyze the following first Check the connector external exclusion and varistor to see if they short circuit Then check the connector to see whether it is short circuit when it is welded b Failure of a single button This situation needs to check whether the beneath of the DOME key is dirty If the problem still ex...

Page 17: ...Page 17 of 22 2 2 4 2 Analysis of Display module circuit Display module use the 5 0 FHD LCD 2 2 4 3 FM Module FM adopts the design of MT 6628 ...

Page 18: ...nnecting to baseband chip through connector The welding of the connector is the main reason for the camera malfunction Camera Interface Circuit 5million pixel front camera 13 million pixel rear camera Power supply circuit VGP2_PMU _1 8V for camera I O port VGP1_PMU 提供 1 5V for camera core VCAMA_PMU _2 8V for analog power ...

Page 19: ...of 22 2 2 4 5 IO Interface IO applies 5pin standard interface which realize the functions of USB charging and download 2 2 4 6 SIM Card Circuit Switch of dual SIM cards is integrated into baseband SIM Card Tray ...

Page 20: ...Page 20 of 22 2 2 4 7 BT WIFI GPS Circuit BT WiFi GPS are integrated into MT6628 2 2 4 8 G sensor Circuit ...

Page 21: ...Page 21 of 22 2 2 4 9 M sensor Circuit ...

Page 22: ...Page 22 of 22 2 2 4 10 Gyroscope Circuit ...

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