Huawei U8815 Maintenance Manual
  1. Manuals
  2. Brands
  3. Huawei Manuals
  4. Cell Phone
  5. U8815
  6. Maintenance manual

Huawei U8815 Maintenance Manual

Hide thumbs Also See for U8815:
Table of Contents

Advertisement

Quick Links

Download this manual
U8815
Maintenance Manual
Issue
1.0
Date
2012-02-13
HUAWEI TECHNOLOGIES CO., LTD.

Advertisement

Table of Contents
loading

Related Manuals for Huawei U8815

Summary of Contents for Huawei U8815

  • Page 1 U8815 Maintenance Manual Issue Date 2012-02-13 HUAWEI TECHNOLOGIES CO., LTD.
  • Page 2 Notice The purchased products, services and features are stipulated by the contract made between Huawei and the 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"...
  • Page 3 Maintenance support team 2012-02-23 Approved by Date Service representative 2012-02-23 Change History Date Version Change Reason Section Description Author 2012-02-23 V1.0 Released the first draft. R&D personnel Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 4: Table Of Contents

    9.3.3 Troubleshooting ............................ 40 9.4 Peripheral Circuits ............................44 9.4.1 Display Screen ............................44 9.4.2 Vibration ............................... 48 9.4.3 Call Reception ............................49 9.4.4 Call Transmission ..........................53 Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
  • Page 5 10 Solder Points on the PCB and BGA Chip................66 11 Performance Test ........................69 11.1 Keys ................................69 11.2 MMI Test ..............................70 11.3 Voice Call Test .............................. 71 Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
  • Page 6 U8815 Maintenance Manual Figures Figures Figure 1-1 Appearance of the U8815 handset ....................... 1 Figure 3-1 Exploded view diagram ........................4 Figure 4-1 PCBA components diagram 1 ......................6 Figure 4-2 PCBA components diagram 2 ......................7 Figure 4-3 PCBA components diagram 3 ......................8 Figure 4-4 PCBA components diagram 4 ......................
  • Page 7 U8815 Maintenance Manual Figures Figure 9-19 Analysis of the U8815 memory interface ..................36 Figure 9-20 Transmitting and receiving circuit block diagram ................37 Figure 9-21 WCDMA IMT PA diagram ......................38 Figure 9-22 WCDMA 850 PA diagram ....................... 39 Figure 9-23 WCDMA PCS PA diagram ......................
  • Page 8 Figure 10-3 Diagram 3 of the solder points on the PCB and BGA chip ............. 67 Figure 10-4 Diagram 4 of the solder points on the PCB and BGA chip ............. 68 Figure 11-1 U8815 handset key ........................... 69 Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright ©...
  • Page 9 Table 9-14 Description of the signals in the circuit diagram in this section ............61 Table 9-15 Description of the signals in the circuit diagram in this section ............65 Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential viii Copyright © Huawei Technologies Co., Ltd.

  • Page 10: Product Introduction

    Maintenance Manual 1 Product Introduction Product Introduction 1.1 Appearance Figure 1-1 shows the appearance of the U8815 handset. Figure 1-1 Appearance of the U8815 handset 1.2 Features Table 1-1 describes the features of the U8815 handset. Table 1-1 Description of the features...
  • Page 11 Headset jack 3.5 mm headset jack Temperature Operating temperature: –10° C to +55° C Storage temperature: –40° C to +70° C Humidity Operating humidity: 5% to 95% RH Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 12: Maintenance Instructions

    2.1 Applicable Scope This document provides maintenance instructions for the technicians at service sites authorized by Huawei. This document is Huawei proprietary and is accessible only for authorized service centers and companies. Although every effort was made to ensure the accuracy of the document, errors may still exist.

  • Page 13: Exploded View

    Table 3-1 List of components in the exploded view Description Quantity Touch panel Front housing (housing A) Liquid crystal display (LCD) display Steel holder Printed circuit board +assembly (PCBA) Rear housing (housing B) Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
  • Page 14 Shielding frame for PA Shielding frame for central processing unit (CPU) Main board printed circuit board (PCB) Shielding frame for radio transceiver (RTR) Shielding frame for power management (PM) Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 15: Pcba Components

    RF failure module 1850–1910 U3302 RF gain U3401 RF gain MHz: no signal, module 1920–1980 module 824–849 weak signal, and MHz: signal failure MHz: signal failure registration failure Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 16: Figure 4-2 Pcba Components Diagram 2

    Failure caused by damage failures signal, and registration failure the U201power management chip PM8029: power failure that prevents the components from working properly Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 17: Figure 4-3 Pcba Components Diagram 3

    Failures caused damage to Failures caused by damage the J102 RF connector: no the J107 antenna spring: signal, weak signal, and no signal, weak signal, and registration failure registration failure Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 18: Software Upgrade

    Before the upgrade, NV items backup is performed (if the handset has not been backed up before). Then the handset restarts and the upgrade starts. The upgrade progress is displayed on the LCD. Figure 5-1 shows the upgrade process diagram. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 19: Figure 5-1 Upgrade Process Diagram

    SD forcible upgrade. It is recommended that you use a charger to perform forcible upgrade. If the download still fails, replace the SD card and try forcible upgrade again. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 20: Maintenance Tools

    Name: soldering iron Usage: to maintain and solder components Name: direct current (DC) power supply Usage: to supply DC current Name: soldering table Usage: to fix the PCBA Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
  • Page 21 Usage: for soldering Name: digital multimeter Usage: to measure during maintenance Name: toolkit Usage: to assemble and disassemble components Name: electric screwdriver Usage: to fasten and remove screws Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 22: Disassembly Procedure

    The following figures show the procedures. 1. Ensure that the electro-static discharge (ESD) wrist strap is properly connected to the ground. 2. Follow the U8815 disassembly instructions. 4. Screw off the four screws on the decorating parts. 3. Remove the battery cover.
  • Page 23 10. Loosen the camera flash according to the figure 9. Loosen the latch between the platelet and the front indication, and loosen the latches between other board housing with the housing opener, and remove the Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
  • Page 24 15. Apply a piece of protective film on the touch panel 16. Unclench the LCD carefully from the two lower of the front housing. corners of the steel holder of the screen. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
  • Page 25 19. Remove the receiver. 22. The disassembly is complete. 21. The flexible printed circuits (FPCs) of volume, Universal Serial BUS (USB) connection, and power-on are on the steel holder. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 26: Assembly Procedure

    Assembly Procedure The following figures show the procedures. 1. Ensure that the ESD wrist strap is properly 2. Follow the U8815 assembly instructions. connected to the ground. 4. Pass the LCD connector through the upper part of 3. Install and fix the receiver.
  • Page 27 On key correctly, and connect the connector. 10. Install the speaker on the rear housing. 9. Fix according to the positioning hole, ring the three screws, and connect to the coaxial cable. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.
  • Page 28 15. Install the battery cover. Fix and press it tightly to 16. The assembly is complete. the latch. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 29: Principles And Failure Analysis

    It is recommended that you restore the phone to its factory defaults. 9.1 Block Diagram and Handset Introduction Figure 9-1 shows the block diagram. Figure 9-1 Block diagram Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 30: Baseband Unit

    In addition, U8815 provides chord music ringtone, vibration, and FM. With the built-in antenna, U8815 adopts a 1350 mAh Li-ion battery. Its standby time can reach up to 420 to 440 hours and the talk time can reach up to 6 to 8 hours depending on the actual network condition.
  • Page 31 9 Principles and Failure Analysis  Analysis U8815 adopts the independent PM8029 power management chip. The power-on mechanism is controlled by Qualcomm codes. The power-on mechanism in the preceding figure is as follows: KPD_PWR_ON tests the voltage, active low. During the power-on process, the PM8029 power management chip converts the main power supply voltage (VHP_PWR) to various voltages listed in the following table.

  • Page 32: Table 9-1 List Of Voltages Converted From Vhp_Pwr By Pm8029 Power Management Chip

    0 to 5 mA. Weak current: Connect your handset to DC power supply. Press the On key. The displayed current ranges from 5 mA to 100 mA. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 33: Figure 9-3 Troubleshooting Process For No Current

    Check the X401 Does the clock and U3101clocks. function properly? Return the handset to the factory for repair. Weak current Figure 9-4 shows the troubleshooting process for weak current. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 34: Figure 9-4 Troubleshooting Process For Weak Current

    32.768 kHz or the output and U3101. of U3101 is 19.2 MHz. Return the handset to the factory for repair. High current Figure 9-5 shows the troubleshooting process for high current. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 35: Charging Management Circuits

    U201. normal? Return the handset to the factory for repair. 9.2.2 Charging Management Circuits  Circuit block diagram The following figures show the charging management circuit diagrams. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 36: Figure 9-6 Charging Management Circuit Diagram 1

    Maintenance Manual 9 Principles and Failure Analysis Figure 9-6 Charging management circuit diagram 1 Figure 9-7 Charging management circuit diagram 2 Figure 9-8 Charging management circuit diagram 3 Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 37: Figure 9-9 Charging Management Circuit Diagram 4

    All the preceding charging methods use the same charging channel: VEXT_DC -> VCHG -> VPH_PWR -> Q201, pin3 -> VBAT. U8815 adopts the dedicated FAN5402UCX power supply chip for 1 A charging, and uses I2C interfaces for communication and control: GPIO13 (I2C_SCL_DCDC) and GPIO13 (I2C_SCL_DCDC).

  • Page 38: Figure 9-10 Troubleshooting Process For Charging Failures

    Is the J1501 battery Replace the J1501 battery connector. connector damaged? Replace the battery. Is the battery damaged? Table 9-2 describes the signals in the circuit diagram in this section. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 39: Clock Circuit

    9.2.3 Clock Circuit  Circuit block diagram The following figures show the clock circuit block diagrams. Figure 9-11 19.2 MHz circuit block diagram 1 Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 40: Figure 9-12 19.2 Mhz Circuit Block Diagram 2

    19.2 MHz clock input is connected to PM8029 and RTR6285A as shown in the preceding figure. The TPK_LO_ADJ controls the precision of clock output. It includes two-stage filter Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 41: Flash Memory Circuit

    RTR6285_TCXO Output from the 19.2MHz clock TCXO Output from the 19.2MHz clock 9.2.4 Flash Memory Circuit  Circuit block diagram The following figures show the flash memory circuit diagrams. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 42: Figure 9-15 Flash Memory Circuit Diagram 1

    U8815 Maintenance Manual 9 Principles and Failure Analysis Figure 9-15 Flash memory circuit diagram 1 Figure 9-16 Flash memory circuit diagram 2 Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 43: Figure 9-17 Flash Memory Circuit Diagram 3

    U8815 Maintenance Manual 9 Principles and Failure Analysis Figure 9-17 Flash memory circuit diagram 3 Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 44: Figure 9-18 Flash Memory Circuit Diagram 4

    LPDDR2 is connected to the MSM8255-0 in PoP (Package-on-package) mode. Meanwhile, the MSM7227A can also visit the external storage eMMC through a low-speed bus (EBI2), as shown in the following figure. Figure 9-19 shows the analysis of the U8815 memory interface. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential...

  • Page 45: Figure 9-19 Analysis Of The U8815 Memory Interface

    Maintenance Manual 9 Principles and Failure Analysis Figure 9-19 Analysis of the U8815 memory interface The EMMC adopts 8-bit data cable for data transmission, and the U8815 adopts 4 GB EMMC. Troubleshooting Process Failure: The handset cannot be powered on, or the power-on current is less than 100 mA.

  • Page 46: Rf Unit

    Circuit Analysis The model of the RF switch behind the main antenna is LMSP4LMA_550_A, and the control logic table of the switch is shown in Table 9-5: Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 47: Power Amplifier

    These control signals are provided by MSM722A. 9.3.2 Power Amplifier  Circuit block diagram The following figures show various power amplifier (PA) circuit diagrams. Figure 9-21 WCDMA IMT PA diagram Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 48: Figure 9-22 Wcdma 850 Pa Diagram

    U8815 Maintenance Manual 9 Principles and Failure Analysis Figure 9-22 WCDMA 850 PA diagram Figure 9-23 WCDMA PCS PA diagram Figure 9-24 GSM Quad_band_PA diagram Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 49: Troubleshooting

    Figure 9-26 Diagram of dualband RF transmitting and receiving by using RTR6285A chip 9.3.3 Troubleshooting  Troubleshooting process Failure: Receiving failure Solution: use W2100 as an example Figure 9-27 shows the troubleshooting process for receiving failure. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 50: Figure 9-27 Troubleshooting Process For Receiving Failure

    Check the control signals of U3202 switch using a multimeter or an oscilloscope. The truth table for control signals is as follows: Table 9-6 describes truths for control signals. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 51: Table 9-6 Truths For Control Signals

    Ensure that the SIM card and antenna are installed properly, and then detect the handset according to the following procedure. Figure 9-28 shows the troubleshooting process for transmission failure. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 52: Figure 9-28 Troubleshooting Process For Transmission Failure

    Supplies power for GPS 2.85 V VREG_RFRX1 Supplies power for RTR6285A 2.1 V VREG_RFTX Supplies power for RTR6285A 2.7 V VREG_S3 Supplies power for RTR6285A 1.8 V Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 53: Peripheral Circuits

    Adjusts the PA gain. None PA_RANGE1 Adjusts the PA gain. None 9.4 Peripheral Circuits 9.4.1 Display Screen  Circuit block diagram The following figures show display screen circuit diagrams. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 54: Figure 9-29 Display Screen Circuit Diagram 1

    U8815 Maintenance Manual 9 Principles and Failure Analysis Figure 9-29 Display screen circuit diagram 1 Figure 9-30 Display screen circuit diagram 2 Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 55: Figure 9-31 Display Screen Circuit Diagram 3

    The U8815 adopts TFT4.0 LCD with a resolution of 800 x 480 pixels. The LCD of the U8815 employs the MIPI interface. It requires only two pairs of low voltage differential signal (LVDS) cables and a pair of power cables, and supports 60 Hz refreshment rate.

  • Page 56: Figure 9-32 Troubleshooting Process For No Lcd Display

    VREG_L12_2P85 LCD analog voltage 2.85 VREG_S3 I/O connector digital voltage MIPI_DSI_LANE2_P Differential signal+ MIPI_DSI_LANE2_N Differential signal- MIPI_DSI_LANE1_P Differential signal+ MIPI_DSI_LANE1_P Differential signal- LCD_RST LCD power-on reset signal Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 57: Vibration

    PCBA. When the motor is not vibrating, VPH_PWR and VIB_DRV_N are both at high level.  Troubleshooting Process Failure: The motor fails to vibrate. Solution: Figure 9-34 shows the vibration maintenance process. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 58: Call Reception

    None power to the motor VIB_DRV_N The driver signal pin of the motor, None connected to the motor's negative electrode 9.4.3 Call Reception  Circuit block diagram Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 59: Figure 9-35 Call Reception Circuit Diagram 1

    The following figures show the call reception circuit diagrams. Figure 9-35 Call reception circuit diagram 1 Figure 9-36 Call reception circuit diagram 2 Figure 9-37 Call reception circuit diagram 3 Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 60: Figure 9-38 Call Reception Circuit Diagram 4

    U8815 provides three audio outputs: Receiver output, outputting signal through PM8029. Speaker output, output by PM8029 to the speaker through the power amplifier. Headset output. U8815 adopts binaural headset. Table 9-10 describes the three audio outputs. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential...

  • Page 61: Table 9-10 Audio Output

    Troubleshooting process Failure: After a call is established, no sound can be heard by the other party. Solution: Figure 9-40 shows the troubleshooting process for sound failure. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 62: Call Transmission

    Do the U2002 neighboring circuits encounter cold joint or soldering offset? Return the handset to the factory for repair. 9.4.4 Call Transmission  Circuit block diagram Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 63: Figure 9-41 Primary Handset Microphone Circuit Diagram

    9 Principles and Failure Analysis Figure 9-41 shows the primary handset microphone circuit diagram. Figure 9-41 Primary handset microphone circuit diagram Figure 9-42 shows the secondary handset microphone circuit diagram. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 64: Figure 9-42 Secondary Handset Microphone Circuit Diagram

     Analysis The primary and secondary microphones on the U8815 board collect different audio signals by processing the MICs on the handset upper and lower parts, filtering the environmental noises. The two microphones are powered by means of HSED_MICBIAS (headset MIC PM8029 HSED_BIAS1), SND_MICBIAS (secondary MIC PM8029 HSED_BIAS2), and MSM_MICBIAS (primary MIC 7227A MIC_BIAS).

  • Page 65: Figure 9-43 Troubleshooting Process For Sound Failure

    Input from the primary microphone. None AUXI_P Input from the secondary microphone. None AUXI_N Input from the secondary microphone. None MSM_MICBIAS Bias voltage of the primary microphone None Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 66: Headset

    The headset MIC is supplied with power by MIC_BIAS1 (PM8029/HSED_BIAS1), and it is used for headset answer detection. The headset of the U8815 is compatible with two line sequences. The iphone's headset line sequence is compatible by default. The pull-up voltage is L19 2.6 V.

  • Page 67: Figure 9-45 Troubleshooting Process For No Sound From The Headset Failure

    Input from the headset microphone None MIC2_N Input from the headset microphone None HSED_ADC_DET Headset microphone test Voltage change HS_DETECT Headphone connect test Voltage change GND_MIC3 Headset MIC grounding signal None Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 68: Sim Card

    Figure 9-46 shows the SIM card circuit diagram. Figure 9-46 SIM card circuit diagram  Analysis The signal input and output of the U8815 SIM card interface are controlled by PM8029.  Troubleshooting Process Failure: The handset cannot detect the UIM card.

  • Page 69: I/O Connector

    UIM card reset signal None NFC_SWIO_UIM Communication signals between None the UIM card and the near field communication (NFC) 9.4.7 I/O Connector Figure 9-48 shows the I/O connector circuit diagram. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 70: Microsd Card Connector

    Charging current input High level, 5 V USB_DM Digital signal None USB_DP Digital signal None 9.4.8 microSD Card Connector Figure 9-49 shows the microSD card connector circuit diagram. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 71: Figure 9-49 Microsd Card Connector Circuit Diagram

    U1601 is added to prevent electrostatic and for EMI filtering.  Troubleshooting Process Failure: The microSD card cannot be detected or read. Solution: Figure 9-50 shows the troubleshooting process for micorSD card read failure. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 72: Figure 9-50 Troubleshooting Process For Micorsd Card Read Failure

    Return the handset to the factory for repair. 9.4.9 FM The following figures show the FM circuit diagrams. Figure 9-51 FM circuit diagram 1 Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 73: Figure 9-52 Fm Circuit Diagram 2

     Analysis With the built-in FM function, U8815 adopts the BROADCOM BCM4330 chip to receive and process FM signals. The BCM4330 chip integrates the functions of FM, BT, and WLAN. For information about the FM antenna, see description about the headset connector. The FM radio uses a headset as the antenna.

  • Page 74: Figure 9-54 Troubleshooting Process For Fm Radio Failure

    VDD_LN_1P2 Supplies power to the BCM4330 chip 1.2 V FM_OUT_L The signal is output from the FM. None FM_OUT_R The signal is output from the FM. None Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 75: Solder Points On The Pcb And Bga Chip

    Green (R:0, G:255, B:0) : Ground point Blue (R:0, G:0, B:255) : Solder point Figure 10-1 Diagram 1 of the solder points on the PCB and BGA chip Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 76: Figure 10-2 Diagram 2 Of The Solder Points On The Pcb And Bga Chip

    Figure 10-2 Diagram 2 of the solder points on the PCB and BGA chip Figure 10-3 Diagram 3 of the solder points on the PCB and BGA chip Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 77: Figure 10-4 Diagram 4 Of The Solder Points On The Pcb And Bga Chip

    U8815 Maintenance Manual 10 Solder Points on the PCB and BGA Chip Figure 10-4 Diagram 4 of the solder points on the PCB and BGA chip Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 78: Performance Test

    U8815 Maintenance Manual 11 Performance Test Performance Test 11.1 Keys Figure 11-1 shows the U8815 handset keys. Figure 11-1 U8815 handset key On/Off/Unlock key Headset holder Volume+ Volume- Menu Homepage Back Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 79: Mmi Test

    19. Compass test: Conduct this test during the gravity induction test. 20. Wi-Fi test: Check whether Wi-Fi information is available. 21. Display test results: Test failure items are displayed. Select failed items for another test separately. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

  • Page 80: Voice Call Test

    If no problem is found during the test, finish the voice call test. If any problem is found, troubleshoot the phone or send it to an advanced service site for repair. Issue 1.0 (2012-02-13) Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

Table of Contents