Huawei U8655N Maintenance Manual Download Page 11

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U8655
Maintenance Manual

4 Components on the PCBA

Issue 1.0 (2012-02-23)

Huawei Proprietary and Confidential

Components on the PCBA

J1001camera connector

Failure of this component
can cause:

Camera shooting failure.

J1401 SIM card holder

Failure of this component
can cause:

SIM card failure.

J1402 SD card holder

Failure of this component
can cause:

SD card failure.

U601 Flash memory chip

Failure of this component
can cause:

Power-on failure, software
are malfunction.

U401 CPU, MSM7225A

Failure of this component
can cause:

Power-on failure, phone
system crash, RF failure.

U4401 NFC module

Failure of this component
can cause:

NFC function failure.

U3302 power module, PA

Failure of this component
can cause:

W2100MHz transmission
failure.

U902 motor

Failure of this component
can cause:

Vibration failure.

U3304 duplexer

Failure of this component
can cause:

W2100MHz transmission
and reception failure.

U1402 SD card filter

Failure of this component
can cause:

SD card failure.

U1303 voltage regulator

Failure of this component
can cause:

LCD backlight failure.

U6000 Wi-Fi/Bluetooth/FM
3-in-1 chip

Failure of this component
can cause:

WiFi, Bluetooth and FM
failure.

U201 power management
chip, PM8029

Failure of this component
can cause:

Power-on failure.

X301 crystal oscillator
32.768KHz

Failure of this component
can cause:

Power-on failure.

J1605 ZIF connector

Failure of this component
can cause:

Volume key failure.

U1204 accelerator

Failure of this component
can cause:

Accelerator failure.

U3202 RF switch

Failure of this component
can cause:

RF failure.

U3201 RF connector

Failure of this component
can cause:

RF failure.

J1101 headset jack

Failure of this component
can cause:

Headset failure.

J1601 BTB connector

Failure of this component
can cause:

Touchscreen panel failure.

J902 battery connector

Failure of this component
can cause:

Power-on failure.

U4101 GPS LNA

Failure of this component
can cause:

GPS failure.

J11302 BTB connector

Failure of this component
can cause:

Display failure.

Summary of Contents for U8655N

Page 1: ...U8655N Maintenance Manual Issue 1 0 Date 2012 09 27 HUAWEI TECHNOLOGIES CO LTD ...

Page 2: ...he customer All or part of the products services and features described in this document may not be within the purchase scope or the usage scope Unless otherwise specified in the contract all statements information and recommendations in this document are provided AS IS without warranties guarantees or representations of any kind either express or implied The information in this document is subjec...

Page 3: ...ntial Copyright Huawei Technologies Co Ltd ii About This Document Purpose Prepared by R D Date Reviewed by Maintenance support team Date Approved by Service representative Date Change History Date Version Change Reason Revised Section Description Author 2012 02 20 V1 0 Released the first issue R D ...

Page 4: ...Information 3 3 Exploded View 4 4 Components on the PCBA 6 5 Software Upgrade 8 5 1 Upgrade Preparation 8 5 2 Upgrade Procedure 8 6 Maintenance Tools 10 7 Disassembly Procedure 12 8 Assembly Procedure 17 9 Principles and Failure Analysis 21 9 1 Block Diagram 21 9 1 1 Function Description of the PCBA 22 9 2 Baseband Unit 25 9 2 1 Power on Management Circuits 25 9 2 2 Charging Management Circuits 29...

Page 5: ...Indicator and Touch Key Backlight Circuits 43 9 4 7 Battery Connector 44 9 4 8 Accelerometer 45 9 4 9 Proximity and Illuminance Sensor 45 9 4 10 Vibration Motor 47 9 4 11 Receiver 48 9 4 12 Microphone 50 9 4 13 Touchscreen Panel 51 9 4 14 SIM Card 52 9 4 15 microSD Card 53 9 4 16 NFC 54 10 Solder Points on the PCB and BGA Chip 59 11 Functional Tests 64 11 1 MMI Test 64 11 2 Voice Call Test 67 ...

Page 6: ...2 23 Huawei Proprietary and Confidential Copyright Huawei Technologies Co Ltd 1 1 Product Introduction 1 1 Appearance 1 2 Specifications Category Description Dimensions H x W x D 116 9 mm x 61 4 mm x 12 2 mm Technical standard U8655N W2100 W900 GSM850 900 1800 1900 ...

Page 7: ... UL 1930 1990 MHz DL Weight 125 g with battery Form factor Bar Antenna Built in UIM SIM USIM Charger 5 V 1000 mA Battery Type Li ion Capacity 1250 mAh Standby time 220 250 hours network dependent Talk time 210 minutes network dependent Display Resolution 320 x 480 pixels Type TFT LCD Color 262K Size 3 5 inches Connectors Charging port micro USB connector USB port micro USB connector microSD card i...

Page 8: ...ice 2 2 Precautions Only qualified technicians are allowed to perform repair and calibration Perform all operations in electrostatic discharge ESD rooms and wear ESD wrist straps throughout the operations Ensure that all components screws and insulators are properly installed after repair and calibration and that all cables and wires are installed and connected correctly Ensure that the soldering ...

Page 9: ...w The components listed in the following table are structural parts of the phone and cannot be used as reference when requesting spare parts Table 3 1 List of components in the exploded view drawing No Item Quantity 1 U8655N_Cover A assembly 1 2 Touchscreen panel 1 3 U8655N_Cover B assembly 1 4 U8655N_Battery cover assembly 1 5 U8655N_Volume key 1 1 5 ...

Page 10: ...655N_PA shielding cover 1 10 U8655N_Proximity and illuminance sensor sealing sheath 1 11 U8655N_MIC_sheath 1 12 U8655N_LCD_conductive fabric 2 13 U8655N_Headset insulation film 1 14 U8655N_USB_adhesive film 1 15 Screw M1 4 3 5 1 16 Diversity antenna and Wi Fi antenna 1 17 Bluetooth antenna 1 18 Main antenna 1 19 LCD 1 20 Power key flexible flat cable FFC 1 21 Receiver 1 22 PCBA 1 23 Volume key FFC...

Page 11: ...sion and reception failure U1402 SD card filter Failure of this component can cause SD card failure U1303 voltage regulator Failure of this component can cause LCD backlight failure U6000 Wi Fi Bluetooth FM 3 in 1 chip Failure of this component can cause WiFi Bluetooth and FM failure U201 power management chip PM8029 Failure of this component can cause Power on failure X301 crystal oscillator 32 7...

Page 12: ...dule PA Failure of this component can cause GSM transmission failure J901 IO connector Failure of this component can cause Charging failure data communication failure D1200 tricolor indicator Failure of this component can cause Tricolor indicator failure F901 fuse Failure of this component can cause Charging failure U3401 power module PA Failure of this component can cause W900MHz transmission fai...

Page 13: ...de pack vendor_XXX_XXX UPDATE APP Upgrade method Using the microSD card Normal upgrade Forcible upgrade 5 2 Upgrade Procedure 1 Format the microSD card 2 Create a folder named dload in the root directory of the microSD card 3 Copy the upgrade file to the dload folder 4 Install the microSD card on the phone Power the phone on and enter 2846579 on the idle screen 5 Select SD Upgrade then Yes to star...

Page 14: ...bly upgrade the phone Install the battery on the phone if the screen is jittering remove the battery and wait for five seconds before installing the battery again Press and hold the Volume and Volume keys and press the Power key The phone enters the SD forcible upgrade mode in which the upgrade process is similar to the normal upgrade While the phone has no battery installed press and hold the Vol...

Page 15: ...hnologies Co Ltd 10 6 Maintenance Tools Name constant temperature hot air blower gun Usage to heat components Name constant temperature heat gun Usage to heat components Name soldering iron Usage to solder components Name DC regulated power supply Usage to supply DC power Name soldering table Usage to secure the main PCBA ...

Page 16: ...ietary and Confidential Copyright Huawei Technologies Co Ltd 11 Name lead free solder wire Usage soldering Name digital multimeter Usage to measure during repair Name toolkit Usage to assemble and disassemble components Name electric screwdriver Usage to fasten and remove screws ...

Page 17: ...onfidential Copyright Huawei Technologies Co Ltd 12 7 Disassembly Procedure 1 Wear an ESD wrist strap and ensure that the strap is grounded properly 2 Remove the battery cover Press the upper part of the battery cover and push it towards the bottom 3 Remove the battery U8655N before disassembly ...

Page 18: ...ential Copyright Huawei Technologies Co Ltd 13 4 Remove the six screws from cover B 5 Use the disassembly tab to release the latch in the upper right corner 6 Use the disassembly tab to release the latch in the upper left corner 7 Use a cover opener to release the latches between cover A and cover B ...

Page 19: ...opyright Huawei Technologies Co Ltd 14 13 Remove the proximity and illuminance sensor sheath and the microphone sheath 11 Release the two latches in the PCBA 10 Disconnect the BTB connector cable between the touchscreen panel and the LCD 8 Remove the volume key 9 Release the volume key FPC 12 Remove the PCBA ...

Page 20: ...ial Copyright Huawei Technologies Co Ltd 15 16 Apply a protective film on the LCD 14 Release the BTB connector and remove the camera Release the ZIF connector and remove the volume key FPC 15 Release the LCD latches and remove the LCD 17 Apply a protective film on the inner side of the touchscreen panel ...

Page 21: ...7 Disassembly Procedure Issue 1 0 2012 02 23 Huawei Proprietary and Confidential Copyright Huawei Technologies Co Ltd 16 19 Remove the receiver 20 Remove the speaker 21 The phone is now disassembled 18 Remove the Power key FPC ...

Page 22: ...uawei Technologies Co Ltd 17 8 Assembly Procedure U8655N before assembly 1 Wear an ESD wrist strap and ensure that the strap is grounded properly 2 Install the camera on the PCBA and snap the BTB connector in place Install the volume key FPC into the ZIF connector and attach the adhesive film 3 Install the receiver ...

Page 23: ...ower key FPC 5 Remove the protective film from the touchscreen panel 6 Remove the protective film from the LCD 7 Install the LCD Ensure that the two latches are snapped in place and that the LCD is even 8 Install the PCBA Insert the USB port into cover A and then snap the PCBA downward in place 9 Gently press the PCBA to close the latches to secure the PCBA ...

Page 24: ...into cover B 10 Snap the LCD s BTB connector and then the touchscreen panel s BTB connector in place 11 Install the volume key Attach the volume key FPC to the metal piece on cover A and then install the volume key 12 Install the speaker 15 Install the battery Insert it into the battery compartment bottom first 13 Install cover B Snap cover B s bottom and press its top ...

Page 25: ...U8655 Maintenance Manual 8 Assembly Procedure Issue 1 0 2012 02 23 Huawei Proprietary and Confidential Copyright Huawei Technologies Co Ltd 20 17 The phone is now assembled 16 Install the battery cover ...

Page 26: ...e U8655N uses the MSM7225A is the baseband signal processing chip mainly responsible for processing the input and output of IMGE VIDEO AUDIO MEMEO SUPPORT RF INTERFACES and CONECTIVITY signals The baseband chip provides keypad LCD SD card Wi Fi Bluetooth camera and microphone interfaces The PM8029 is mainly responsible for Detecting the connection and disconnection of the external power supply Sup...

Page 27: ...odulation of WCDMA GPS and GSM signals Application subsystem The subsystem includes ARM A5 processor application DSP and dedicated data mover The A5 processor has a clock rate of 800 MHz supporting function modules such as the microSD card EBI2 UART USIM I2C GPIO and clock modules User interface processing unit Provides camera PCM broadband codec vocoder RF HKADC LCD SD card USB UART USIM card SBI...

Page 28: ...and low frequency bands The antennas are the main antenna GPS antenna diversity antenna Wi Fi Bluetooth antenna FM antenna headset and NFC antenna Coupler Power coupler Couples part of the power output from the WCDMA power amplifier to the RTR6285A for power monitoring User interface subsystem UART interface MSM7225A subsystem s UART1 interface for Bluetooth USB interface Driver protection circuit...

Page 29: ...face Driver mode connection mode motor When there is an incoming call the motor can vibrate notify the user of the call NFC I2C interface control Performs proximity sensing function Proximity and illuminance sensor I2C interface control Senses the intensity of environmental light for adjusting the LCD and keypad backlight brightness Detects the distance between the phone and the user s skin and tu...

Page 30: ...power saving analysis the board software manages the power supplies to the units on the board to reduce power consumption RTC The built in RTC circuit uses a sleep clock of 32 768 kHz to provide precise time HKADC Contains 8 MPP interfaces Analog to digital conversion can be implemented inside the PM8029 TCXO driver The PM8029 has a built in TCXO driver providing two analog signal output channels ...

Page 31: ...al of 24 output channels The follow table lists the voltage regulator parameters Table 9 2 Voltage regulator specifications Troubleshooting Process To troubleshoot the power on failure firstly check whether the I O connector battery connector is damaged If the I O connector battery connector is not damaged use a DC regulated power supply to supply power to the phone and test the phone s current Th...

Page 32: ...lysis Issue 1 0 2012 02 23 Huawei Proprietary and Confidential Copyright Huawei Technologies Co Ltd 27 Replace J902 N Power on failure no current Is the battery connector J902 normal Replace Q201 N Is Q201 normal Y Re solder or replace U201 Y Weak current ...

Page 33: ...nt End Is U201 output Voltage normal Y Y Does X301 have 32 768 kHz output Replace U601 and reinstall The phone s firmware Is the Problem solved Y Y Replace U401 N N Replace U201 Replace X301 End Excessive current Excessive current is caused by short circuits When excessive current occurs to prevent damage to components do not connect the charger to the phone Power on failure due to excessive curre...

Page 34: ...Co Ltd 29 N N Test the VBAT circuit Is it a short circuit Y Y N N N N Y Y Powe on failure excessive current Check whether VPH_PWR and PM output are short circuited Is J902 normal Y Y Is Q201 normal Remove U201 Do short circuits still exist Y Y Replace U401 N N Re solder or replace J902 Replacec Q201 Replace U201 9 2 2 Charging Management Circuits ...

Page 35: ...ly soldered N N Is the battery s in good contact with the battery connector Does VPH_PWR have voltage Y Y End Y Y Re solder J901 Repair or replace J902 Replace U901 Is there voltage difference between Q201 s pin 2 and pin 3 N N Replace Q201 Y Y Is the battery damaged Y Y Replace the battery N N 9 3 RF Unit 9 3 1 RF Failure Troubleshooting Transmission Failure GSM DCS transmission failure Before st...

Page 36: ...put and DCS output approximately 33 dBm and 30 dBm respectively Check U3202 and U401 Check U3501 Y N Y Y Y N N Do U3801 s pin A10 and pin A9 have output Check U3801 N Y NOTE The following tables describe the working status of the GSM DCS power amplifier U3501 GSM_PA_EN PA H ON L OFF GSM_PA_BAND MODE L GSM850 900 H DCS1800 1900 H voltage higher than 1 3 V L voltage lower than 0 5 V WCDMA transmissi...

Page 37: ...ontrol signals normal Check U401 Is the insertion loss between U3304 s pin 1 and pin 3 approximately 1 1 1 4 dB Check U3202 and U401 Check U3304 Y N Y Y Y N N Is U3301 s output 24 dB Check U3301 N Y Y Y Is the insertion loss between U3302 s pin 2 and pin 9 approximately 0 6 dB Check U3302 N Check U3801 N Does U3801 s pin A7 have output NOTE The following tables describe the working status of the W...

Page 38: ... functions share one antenna and one SP3T RF switch The MSM7225A provides PCM and UART interfaces that are directly connected with the Bluetooth module s PCM and UART signal output The following table describes the signals definitions MSM7225A Signal Definition GPIO_44 UART1_CTS_N The ready to receive signal from the host the MSM7225A to the slave the BCM4330 GPIO_43 UART1_RFR_N The clear to send ...

Page 39: ...The following table describes the signals definitions BCM4330 Network MSM7225A Description FM_RXP FM_ANT FM antenna headset FM_RXN FM_VDD2P5 SR_AVDD2P5 FM_AOUT1 FM_OUT_L PM8029 LINE_IN_LP FM OUTPUT FM_AOUT2 FM_OUT_R PM8029 LINE_IN_RM FM OUTPUT 9 4 Peripheral Circuits 9 4 1 Display The MSM7225A uses MIPI interfaces to send instructions and data to the LCD The U8655N s LCD uses MIPI interfaces suppo...

Page 40: ...ation signal Frame synchronization clock MDP_VSYNC_P GPIO97 Clock signal MIPI clock MIPI_DSI_CLK_P MIPI_DSI_CLK_P MIPI clock MIPI_DSI_CLK_N MIPI_DSI_CLK_N Control signal Reset signal LCD_RESET_N GPIO129 Identification signal LCD model identification LCD_ID0 GPIO9 PM8029 LCD model identification LCD_ID1 GPIO10 PM8029 U8655N s LCD backlight control The U8655N uses a 3 5 inch LCD whose backlight is p...

Page 41: ...ht Huawei Technologies Co Ltd 36 Backlight signals The anode of the backlight LED LED_A The anode of the backlight LED The cathode of the backlight LED LED_K The cathode of the backlight LED Brightness control signals from the LCD PWM_OUT Reserved Brightness control signals from the phone s main chip LCD_BL_PWM GPIO1 PM8029 ...

Page 42: ...o the factory Check whether J1302is snapped in place If it is not in place snap it again Is the problem solved End Y N Reinstall the phone s firmware Is the problem solved End Y N Replace the LCD Is the problem solved End Y N 9 4 2 Camera The U8655N uses a 3 2 megapixel full frame camera The 3 2 megapixel full frame camera uses a 24 pin BTB connector and is controlled by the I2C bus The data is tr...

Page 43: ... Camera autofocus motor control signal I2C0_SCL GPIO_060 MSM7225A 1 8 I2C control signal I2C0_SDA GPIO_061 MSM7225A 1 8 MCAMIF_RESET GPIO_049 MSM7225A 1 8 Reset signal MCAMIF_ID GPIO_9 MSM7225A 1 8 Module supplier identification MIPI_CSI2_CLK_P MIPI_CSI2_CLK_P MIPI clock MIPI_CSI2_CLK_N MIPI_CSI2_CLK_N MIPI clock MIPI_CSI2_LANE1_P MIPI_CSI2_LANE1_P Data communication signal MIPI_CSI2_LANE1_N MIPI_...

Page 44: ...logies Co Ltd 39 Troubleshooting Camera Failure Failure to take photos or record video using the camera Replace the camera Is the problem solved End Is J1001 poorly soldered or are its contacts defective Return the phone to the factory Re solder or replace J1001 Y N Y Reinstall the phone s firmware Is the problem solved End Y N N 9 4 3 USB ...

Page 45: ...N N 9 4 4 Headset Jack The headset jack is a 3 5 mm headset jack When the headset jack has no headset inserted the headset jack s pin 3 and pin 4 are open and the headset detection voltage is at high level After a headset is inserted pin 3 and pin 4 are closed and the headset detection voltage is at low level indicating the insertion of a headset The HS_DETECT GPIO86 pin is used to detect the head...

Page 46: ...und comes from the headset during a call After a call is established no sound can be heard from the headset Is a headset icon displayed on the screen Replace the headset jack Replace the headset Is the problem solved Return the phone to the factory End Y Y N Is the in call volume set to a normal level End N N Y The headset button cannot be used to answer a call ...

Page 47: ...to the factory Check that J1101 is properly soldered N Replace the headset Is the problem solv ed End Y Y N 9 4 5 Keys The U8655N has six keys three of which are the Menu Home and Back keys on the touchscreen panel The MSM7225A s GPIO_42 and GPIO_41 pins are connected to the volume up and down keys The side key FPC is connected to the PCBA via the ZIF connector J1605 The Power key press is detecte...

Page 48: ...light Circuits The U8655N s status indicator tricolor indicator provides red green and blue light sources that are driven by the PM8029 s three LED drivers Light Source Driver Pin PM8029 Description Red LED_RED_DRV_N MPP3 Adjusted using electric current Green LED_GREEN_DRV_N MPP5 Adjusted using electric current Blue LED_BLUE_DRV_N MPP8 Adjusted using electric current The KYPD_DRV_N PM8029 is used ...

Page 49: ...02 23 Huawei Proprietary and Confidential Copyright Huawei Technologies Co Ltd 44 Keypad Backlight Driver VPH_PWR Power supply Backlight power supply KPD_DRV_N Backlight driver pin When this pin s voltage is at low level the two backlight LEDs turns on 9 4 7 Battery Connector ...

Page 50: ... Accelerometer Component Pin Network MSM7225A Pin Description SCL I2C1_SCL GPIO_131 I2C bus SDA I2C1_SDA GPIO_132 INT1 MEMS_INT1 GPIO_28 Accelerometer interrupt signal INT2 MEMS_INT2 GPIO_111 Accelerometer interrupt signal sleep 9 4 9 Proximity and Illuminance Sensor The U8655N has a proximity and illuminance sensor The following figure shows the sensor circuit ...

Page 51: ... INT PRO_INT GPIO_17 3 in 1 interrupt signal Functions Detect the intensity of environmental light Detect the proximity of objects The phone s display does not turn off when near the user s ear during a call Is U1207 poorly soldered or dirty Re solder clean or replace U1207 Reinstall the phone s firmware Is the problem solved Return the phone to the factory End Y N Y Is the touchscreen panel s ill...

Page 52: ...Ltd 47 9 4 10 Vibration Motor The motor driver current is controlled by PM VIB_DRV_N Troubleshooting Vibration Failure Vibration failure Is the voltage on VIB_DRV_N equal to the battery voltage Replace D902 Replace the motor Is the problem solved Return the phone to the factory End Y N Y Reinstall the phone s firmware Is the problem solved End Y N N ...

Page 53: ...rphone output from the MSM chip The following figure shows the circuit The MSM chip s EARI output signal is connected to the receiver Bypass capacitors are added to the signal traces The circuit shown in the previous figure is designed for compatibility L1508 L1510 and U1501 are reserved for the HAC function and are not soldered on the U8655N D1503 and D1504 are the ESD protection components on th...

Page 54: ...ies Co Ltd 49 Troubleshooting the Failure that No Sound Can Be Heard During a Call No sound is heard during a call Replace the receiver Is the problem solved End Does the phone mistakenly detect the insertion of a headset Return the phone to the factory Replace the headset connector Y N Y Is the in call volume set to a normal level End N N Y ...

Page 55: ...U8655 Maintenance Manual 9 Principles and Failure Analysis Issue 1 0 2012 02 23 Huawei Proprietary and Confidential Copyright Huawei Technologies Co Ltd 50 9 4 12 Microphone ...

Page 56: ...blem solved End Is the MIC_BIAS voltage equal to 1 8 V Return the phone to the factory Check U201 N N Y Reinstall the phone s firmware Is the problem solved End Y Y N 9 4 13 Touchscreen Panel The U8655N s 3 5 inch capacitive touchscreen panel has a touch key area containing three touch keys The backlight LEDs for the three touch keys are located on the PCBA A light guide film is used to guide ligh...

Page 57: ...signal 9 4 14 SIM Card The MSM7225A is not compatible with the SIM card interface The PM8029 s MPP pins are used to convert voltage levels of the signals for communication between the MSM7225A and the SIM card The voltage of VREG_L16_UIM1 can be set to 1 5 3 05 V The USIM interface s operating voltage is usually 1 8 V or 3 0 V The following table describes the voltage level conversion interface of...

Page 58: ...4 15 microSD Card The microSD card connector s SD_DETECT pin is used to detect the insertion of a microSD card When a microSD card is inserted the pin is grounded and its voltage is at low level When no microSD is inserted its voltage is at high level The U1402 is an EMI and ESD protection component for the microSD card The following figure shows the circuit ...

Page 59: ... 16 NFC U8655N supports NFC module function and uses NFC control chip of NXP to receive and process signal when use NFC function normally the battery cover must be covered because of built in antenna the signal NFC_VEN_MOS which is the reset signal of NFC module is controlled by NFC_VEN signal this module uses a clock of 19 2MHz to ensure module work properly ...

Page 60: ...U8655 Maintenance Manual 9 Principles and Failure Analysis Issue 1 0 2012 02 23 Huawei Proprietary and Confidential Copyright Huawei Technologies Co Ltd 55 ...

Page 61: ...U8655 Maintenance Manual 9 Principles and Failure Analysis Issue 1 0 2012 02 23 Huawei Proprietary and Confidential Copyright Huawei Technologies Co Ltd 56 ...

Page 62: ... Failure of NFC swiping Y Y Update the phone s software Is the problem solved N N N N N N Swiping card failure End Is the antenna in good contact with metal dome Y Y Is power output Voltage normal Y Y Return to factory Replace battery covere with antenna Re solder U4401 Signal name Description Voltage or Waveform NFC_VEN_MOS NFC chip reset signal The same voltage of battery ...

Page 63: ...idential Copyright Huawei Technologies Co Ltd 58 Signal name Description Voltage or Waveform NFC_VEN The reset signal from CPU 1 8V NFC_TX1 Contactless Transmitter output1 NFC_TX2 Contactless Transmitter output2 VBAT Battery power Battery voltage 3 6V 4 2V VREG_S3 power 1 8V TCXO_OUT_NFC Clock signal 19 2MHz ...

Page 64: ...02 23 Huawei Proprietary and Confidential Copyright Huawei Technologies Co Ltd 59 10 Solder Points on the PCB and BGA Chip Red R 255 G 0 B 0 Vacant point Green R 0 G 255 B 0 Ground point Blue R 0 G 0 B 255 Solder point Magnified views of sections PM section MSM7225A NAND MCP section ...

Page 65: ...655 Maintenance Manual 10 Solder Points on the PCB and BGA Chip Issue 1 0 2012 02 23 Huawei Proprietary and Confidential Copyright Huawei Technologies Co Ltd 60 Wi Fi Bluetooth FM section RTR8285A section ...

Page 66: ...U8655 Maintenance Manual 10 Solder Points on the PCB and BGA Chip Issue 1 0 2012 02 23 Huawei Proprietary and Confidential Copyright Huawei Technologies Co Ltd 61 Complete PCB view ...

Page 67: ...U8655 Maintenance Manual 10 Solder Points on the PCB and BGA Chip Issue 1 0 2012 02 23 Huawei Proprietary and Confidential Copyright Huawei Technologies Co Ltd 62 ...

Page 68: ...U8655 Maintenance Manual 10 Solder Points on the PCB and BGA Chip Issue 1 0 2012 02 23 Huawei Proprietary and Confidential Copyright Huawei Technologies Co Ltd 63 ...

Page 69: ...rd functions If a microSD card is found and is available the test passes Otherwise the test fails If this test passes the next test automatically starts 2 SIM card test SIM card test Automatically test whether the SIM card can be recognized If the SIM card cannot be recognized a message will be displayed indicating that this test fails If this test passes the next test automatically starts 3 Batte...

Page 70: ...s which are composed of a group of squares one is in middle the other are on edge Place your figure on the touch screen panel and slide your figure sweep each square along the gridline The areas near the route that your figure passes should turn red it will fail if the finger sweeps outside of these squares Press the Volume key to start the next test 10 Approach test The proximity and illuminance ...

Page 71: ...st 17 Mobile phone Headset loopback test Headset Insert the headset Touch the Record button Speak to the headset microphone and then touch the Play button If the headset is normal you can hear the voice recording from the headset s earphones Keep the headset inserted Press the Volume key to start the next test 18 FM test FM test The testing software will detect whether a headset is inserted If no ...

Page 72: ...e phone will search for nearby hotspots and display the MAC addresses of the hotspots that have been found Note This test requires an active hotspot in the testing environment Press the Volume key to start the next test 23 Display test Displaying test results Display the MMI test results Failed test items will be listed 11 2 Voice Call Test 1 Install a UIM card and a battery on the phone 2 Press t...

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