C8813 Service Manual

C8813 Service Manual

V1.0

Directory

Chapter 1 : Introduction

1.1 Appearance

1.2 Product Features

Chapter 2 : Repair information described in Guidelines

2.1 Documentation Instructions

2.2 Maintenance Considerations

2.3 Maintenance guidelines for access to information

Chapter 3 hosts exploded diagram

Chapter 4 motherboard components location map

Chapter 5 Software Upgrade

5.1 before upgrading to prepare

5.2 Upgrading the hardware connection

5.3 USB driver installation

5.3.1 upgrade process

5.3.2 Forced Upgrade

5.4 SD upgrade

5.4.1 SD card normal upgrade

5.4.2 SD card is mandatory upgrade

5.5 Exception Handling

Chapter 6: Repair Tools

Chapter 7: Figure disassemble step

Chapter 8: Installation steps Figure

Chapter 9: Mobile principle and failure analysis

9.1 Block diagram and introduce mobile phone

9.2 baseband unit

9.2. A power management circuit switched

9.2.2 charge management circuit

9.2.3 clock circuit

9.2.4 Flash circuit

9.3 GSM radio unit

9.3.1 CDMA RF transceiver circuit

9.3.2 GSM RF transceiver circuit

9.4 peripheral circuits

9.4.1 Display

9.4.2 Vibration

9.4.3 Receiver and SPK

9.4.4 microphone

9.4.5 headphones

9.4.6 SIM card

9.4.7 IO Interface

9.4.8 SD Card Interface

9.4.9 FM + BT

Chapter 10 :of the PCB and BGA chip solder indication map

Chapter 11: Functional Test

11.1 Keyboard and Features

11.2 MMI test

11.3 Voice Test

Chapter 9 Mobile principle and failure analysis 9.1 Block diagram and introduce mobile phone

C8813 is a Qualcomm MSM8625-based independent research and development of CDMA candy bar

phone, the use of QUALCOMM Incorporated MSM8625 PM8029 ch Board includes MSM8625,

PM8029, RF devices, connected by FPC LCD, Receiver, Speaker by shrapnel and

Motherboard connector, MIC connected to the board by soldering, welding motor SIM card / SD

card soft board, through the connector to the motherboard with

Even. RF antenna connected by shrapnel, with shell structure, batteries, constitutes a whole. In

addition to providing basic voice, Short message function, also supports phone book and SMS saved

in the UIM card and mobile phone two storage modes, support MicroSD card storage. Hardware

The support FM radio and recording function.

C8813 supports color TFT LCD, dot number is 854 × 480; provide external Micro USB type charger

interface, UIM cards

Interface, support for polyphonic ringtones and vibration function, FM function. RF antenna built-in,

optional 1700mAh lithium battery, CDMA standby Time of 400hrs around (with the actual network

related), continuous talk time of about 11 hrs (with the actual network related).

9.2 baseband unit

9.2.1 Boot power management circuits

Circuit diagram:

KPD PWR ON

C8813 Maintenance Manual V1.0

Circuit theory analysis:

C8813 uses separate power management chip PM8029, the principle of all by the power of

Qualcomm code control, power on the map by the principle

KPD_PWR_ON detection voltage is active low. The power mains voltage in the VHP_PWR process by

PM8029 power management chip transfer Change the table below to get a variety of voltage:

Failure analysis process: Can not boot into boot no fault current, low current, high current and other

categories, many machines are due to power anomalies caused, When faced with a similar power

failure, please troubleshoot problems caused by power supply circuit in accordance with

troubleshooting methods.

1 boot no current: DC power boot, press the power button, display the current DC power from 0 to

5mA;

2 Boot Little Current: DC power boot, press the power button, the DC power display current 5mA to

100mA;

3 large boot current: DC power boot, press the power button, the display current 300mA DC power

over;

When the situation C8813 phone can not boot, can fail to judge by observing DC power supply

current.

1. No current

Does not boot

External fake batteries and electrical repairs

Source, press the power button, observe the power

Flow

No current

Whether the keys copper oxide? Y Clean button

N

Measure VPH_PWR

Voltage is normal 3.4 to 4.2 =

Maintenance of power supply voltage N Inspection U201

Y

Check whether the clock is normal? N Check the clock

X301 U3101

Y

Depot Repair

2.A small current

Does not boot



Flow

A small current

Detect PM The output voltage is N Inspection U201

No normal?

Y

Measure X301

The output frequency is = 32.768KHz N Re-welding or

Or replacement X301

U3101 Export 19.2MHz U3101

Y

Depot Repair

3.A large current

Does not boot



Flow

A Large current

Detection J1611 3 Pin Y Detection U201 and

Grounded? J1611

N

U201 detection voltage is normal? N Re-welding

or replace U201

Y

Depot Repair

9.2.2 charge management circuit

Circuit diagram:

circuit theory analysis:

C8813 uses PM8029 power management chip, the internal integration of the charging scheme, there

are three charging status: red trickle power, constant Current charging and constant voltage

charging. Have adopted the same charge path: USB_VCHG → VCHG → VPH_PWR → Q201, pin3 →

VBAT Using FAN5402UCX dedicated power chip 1A charging, using I2C communication and control,

two interfaces GPIO13 (I2C_SCL_DCDC), GPIO98 (I2C_SDA_DCDC). This charge management chip

straight from VCHAG USB interface.Then take power from the I2C control. Output VPH_PWR is

powered PM, while charging the battery.

The functional block diagram as follows:

4-16 charging chip functional block diagram

Charging flow diagram as follows:

Charging flow diagram in Figure 4-17

This chip has three modes: charge mode, boost mode and high-impedance mode. Normal start

charging mode charging process, boost Mode is USB-OTG mode, high-impedance mode is not

charging power saving mode (standby).

When the external power supply (charger or USB) connection to the phone, to determine the

external voltage is greater than VuvloPM, then look VAUXPWR <VLOWV (specific meaning to the

battery voltage is less than the maximum battery voltage). If the battery voltage is maximum, no

charge Electricity; Instead, start the charging process.

Several voltage and current explanation:

V (SHORT) trickle charging, constant current charge starting voltage

V (OREG), constant current charging, constant voltage charging start voltage

IO (CHARGE) constant charging current

I (IN_LIMIT) constant charging current limit, and IO (CHARGE) 2-to-1

I (SHORT) trickle charge current

V (RCH) As the rechargeable battery voltage

By monitoring the cell phone chip CSOUT pin mains voltage, when the battery voltage is less than V

(SHORT), start the trickle charge; When electricity Battery voltage is greater than V (SHORT) is less

than V (OREG) constant current charging starts; When the battery voltage is approximately equal to

V (OREG), constant voltage charging start Electricity; When the charge current is less than a certain

value while the voltage exceeds a certain range V (RCH), stop charging. Chip built-in 15 minutes and

32 seconds timer, saving CPU resources, automatically starts 15 minutes timer that no i2c control,

parameter use to load their own charge. If the CPU via I2C control, then starts a 32 second timer.

Process is as follows:

BQ24152 timer flowchart in Figure 4-18 under charging mode

Actual circuit hardware OTG man received a level greater than 1.4V, the initial charging charging

port is limited to the maximum current the whole 500mA, the charging process to be detected after

a specific software to disable this limit. FAN5402UCX has its own temperature detection function

Able, when the temperature reaches the upper limit TJ TCF, reducing the charge current, stop

charging when when TJ is less than the upper temperature limit TCF10 degrees, heavy New start

charging. When the charging voltage VBUS charge voltage is less than the sleep (VAUXPWR + Vslp)

when, FAN5402UCX into sleep mode to save power. FAN5402UCX can continue charging voltage

detection VBUS, VIN (min) when VBUS is less than the set threshold, Re-determine the phone stops

charging and wait for a TINT. FAN5402UCX with charging overvoltage protection, battery over-

voltage protection Function, battery reign detection, no battery start.

Failure analysis process:

Symptom: The phone is not charging failure is usually the case, there are two: First, after the charger

is connected to the phone, the phone did not respond; Another phone while charging is displayed,

but can not charge the battery. For no charge fault plane, first detected I / O interfaces, Look for any

obvious damage. After the charger is connected to the phone, the phone without charging indicator

After the charger is connected to the phone, the phone has a charging indicator, but you can not

charge the battery

Into the charger is not charging

Charger is working properly? N Replacement charger

Y

Observation USB connector Y J901 welding

J901 whether Weld?

Are there voltage measurement N C231? N Check fuses F901 and

beads LB901

Y

Check whether the charging chip U901 N Replacing U901

Output voltage VPH_PWR

Y

Check whether the output pin 3 Q201? N Replacing Q201

Y

Battery connector J902 is damaged? Y Replace the battery

connector J902

N

If the battery is damaged? Y Change Battery

N

End

This section schematics signal summary:

Signal Name Function Details Test Reference value or waveform chart

USB_VCHG Charger power input.

VCHG External USB powered 0—5 V

charging chip input.

I2C_SCL_DCDC Charge control signal chip. No

I2C_SDA_DCDC Charge control signal chip. No

VPH_PWR The main power supply to the power Supply voltage

supply module here variation range

0-4.2V

BAT_FET_N MOS transistor battery (Q201)

of the control output.

VBAT Battery voltage Battery voltage

variation range

0-4.2V

USB_HS_DP USB differential data positive input No

USB_HS_DN USB differential data positive input. No

9.2.3 clock circuit

Circuit diagram:

19.2MHz


As Figure: 19.2MHz clock output access PM8029 and RTR6285A, TPK_LO_ADJ control precision clock

output. TPK_LO_ADJ has two filter circuit, R204, C232 and R3101, C3101. After PM output to the

host system as the main chip Clock.

32.768kHz crystal oscillator input to the PM8029, the PM output to the system


Symptom: The phone does not boot, or easy to crash, check 32.768kHz crystal oscillator X301

detection and U3101 have not A signal, or the frequency is stable.

Solution: Replace the X301 or U3101, to see whether it is normal, otherwise replace the PM8029.


Signal Name Function Details Test Reference value or waveform chart

XTAL32K _OUT 32.768kHz master clock

signal output terminal

XTAL32K_IN 32.768kHz master clock

signal input terminal

VREG_TCXO 19.2MHz crystal power 2.85V

TRK_LO_ADJ 19.2MHz frequency control NO

signal output

RTR6285_TCXO 19.2MHz clock output

TCXO 19.2MHz clock output

9.2.4 Flash circuit

Circuit diagram:


MSM8625 can be accessed through the high-speed bus EBI1 connected thereto by LPDDR PoP

(Package-on-package), At the same time, but also the low-speed access to external memory bus EBI2

eMMC by one, as shown below:

Figure 4-2 C8813 Mobile Memory Interface Analysis

EMMC uses eight data lines for transmission, C8813 products using the 4G EMMC devices.


Symptom: The phone does not boot or boot currents can rise to tens of mA, Processing methods:

Upgrade or loading software, testing VREG_DCDC_2P85 voltage is normal, if normal peripheral

devices, whether Replace the U1800.


Signal Name Function Details Test Reference value or waveform

Map

SDC3_DATA3 Data line

SDC3_DATA2 Data line SDC3_DATA1 Data line SDC3_DATA0 Data line SDC3_DATA7 Data line SDC3_DATA6 Data line SDC3_DATA5 Data line SDC3_DATA4 Data line

SDC3_CLK Clock

SDC3_CMD Command

VREG_DCDC_2P85 Flash Power 2.85V

VREG_S3 Power supply 1.8V

MSM_RESOUT_N Reset VPH_PWR System power, 2.85V DCDC

chip power supply 9.3 GSM radio unit

The band CDMA GSM switch gating circuit schematics

Switch Select Truth Table

Behind the main antenna RF switch model is 47140032, which control logic list is as follows:

Select the

band

ANT_SEL0 (GPIO75) ANT_SEL1 (GPIO74)

ANT_SEL2 (GPIO73)

ANT_SEL3 (GPIO72)

CDMA CELL TX/RX 0 0 1 0 GSM 900 TX 0 0 0 1 GSM 900 RX 1 x 1 1 GSM 1800 TX 0 0 1 1 GSM 1800 RX 1 x 1 0

GSM 1900 TX 0 0 1 1 GSM 1900 RX 1 x 1 0

Description: on the table "L" voltage range is 0 ~ 0.2V, "H" voltage range 1.8 ~ 3.0V. "X" indicates not

involved. These control signals given by the MSM8625.

9.3.1 CDMA RF transceiver circuit

TX CELL DUPLEXER & PA

CDMA RF Transceiver

9.3.2 GSM RF transceiver circuit

GSM PA inheritance RF selector switch inside.

After RTR6285A using GSM RF transceiver chip.

9.4 peripheral circuits

9.4.1 Display

circuit diagram:


C8813 is optional LCD TFT 4.5 inches, dot number 854 × 480, using the MIPI interface.

C8813 LCD interface products using MIPI, just using two pairs of differential signal lines, a pair of

power lines, support 60Hz refresh rate. With frame synchronization, use GPIO_097 of MDP_VSYNC

synchronization signals as data transmission, to avoid split-screen phenomenon.


Symptom: You can boot but no display LCD

Solution: Check the LCD

No LCD display

Reload software

No normal? Y End

N

Whether the backlight? N Check the L1303, U1303

Y

U1601 whether N Re-welded

Welding good?

Y

Check the connectors N Rest J1302

J1302 whether welding

Good contact?

Y

Depot Repair

(No LCD display repair process)


Signal Name Function Details test reference value or waveform chart

VREG_L12_2P85 LCD analog voltage, 2.85

VREG_S3 I / O port digital voltage 1.8

MIPI_DSI_LANE2_P differential signal + 1.8

MIPI_DSI_LANE2_N differential signal - 1.8

MIPI_DSI_LANE1_P differential signal + 1.8

MIPI_DSI_LANE1_P differential signal - 1.8

LCD_RST LCD power-on reset signal is 1.8

1.8 MDP_VSYNC_P longitudinal frame synchronization signal

LCD_ID0 vendor ID information 1.8

LCD_ID1 vendor ID information 1.8

MIPI_DSI_CLK_P clock differential signal + 1.8

MIPI_DSI_CLK_N differential clock signals - 1.8

9.4.2 Vibration

circuit diagram:


PM8029 pin VIB_DRV_N as a drive pin vibrator motor is placed on the motherboard. When the

motor of appetite, VPH_PWR and VIB_DRV_N are high.

failure analysis process:

Symptom: Motor appetite

Treatment:

No vibration motor

Reload software Y End After normal?

N

Check whether the motor Weld? Y After verification welding

ends N

Measure whether motor-powered Normal? N Vibration test negative

Whether extremely low?

Y

Check the power Replace the motor if Y End

Normal?

N

Depot Repair (No vibration repair process)



VPH_PWR main power supply

to the motor where no

VIB_DRV_N foot motor drive signal,

then no motor negative

9.4.3 Receiver and SPK

SPK¬ circuit diagram:

C8813 offers three audio outputs:

1. Receiver output. The output signal from the CPU.

2. Speaker output. After the PM8029 amplifier output to Speaker.

3 headphone output, C8813 dual channel headphone design.


EAR1_AMP_1_OP output to the receiver without

EAR1_AMP_1_ON output to the receiver without

SPK_OUT_L_P after PM8029 amplifier output to the SPEAKER None SPK_OUT_L_M after PM8029 amplifier output to the SPEAKER None


Symptom: After creating a call by saying no.

Treatment:

After the call is established, then no subject

Reload software

After normal? Y End

N

Check the earpiece volume settings

Set normal? N Adjust the

volume

to see if normal

Y

View receiver even N Re-welded connections

Line is normal?

Y

Are misjudgment

headphones Insert? Y Overhaul

headphone connector

N

Replace the receiver is

No normal? Y END

N

Check the U201 peripheral level

Are Weld Road deviation? Y END

N

Depot Repair

9.4.4 microphone

circuit diagram:

Master Mike:


C8813 board has only one microphone, using HSED_MICBIAS (Headphone MIC PM8029

HSED_BIAS1),, MSM_MICBIAS (MIC 7227A MIC_BIAS) power supply. Failure analysis process:

Symptom: No transmitter failure

Treatment:

After the call is established, no microphone

Reload software

After normal? Y END

N

Re-welding MIC

To see whether it is normal? Y END

N

Check the electrical MICBIAS N Check the

Whether the pressure is normal? C507

Y

Replace the MIC whether

Normal? Y END

N

Depot Repair



MIC1_P main mic input without

MIC1_N main mic input without

MSM_MICBIAS Master Mike bias voltage without

9.4.5 headphones

circuit diagram:


Headphones into the detection by HS_DETECT_N (GPIO_086) pin judgment:

When headphones are plugged in before, HS_DETECT_N is pulled into a high level VREG_S3;

When the headphones are plugged in, HS_DETECT_N is pulled low, a low level.

Headphone MIC power supply uses MIC_BIAS1 (PM8029 / HSED_BIAS1) power, and used the

headset to answer detection.


Symptom: No sound headphones

Treatment: Replace the headset, replace the headphone jack.

After the establishment of the call, the headset

Hear the sound of the call

Check the earpiece volume settings

Set normal? N Re-set the volume

Y

Replacing normal headphones

Normal? Y End

N

Plug in your headphones

HS_DETECT whether

Voltage change? N Replace the headset seat

Y

Depot Repair



FM_ANT FM antenna without

HPH_OUT_L stereo headphone output without

HPH_OUT_R stereo headphone output without

HSED_MICBIAS headset MIC bias voltage signal

MIC2_P headphones without MIC input

MIC2_N headphones without MIC input

HSED_ADC_DET headset MIC detect voltage changes

HS_DETECT headphones into the detection voltage change

GND_MIC3 headset MIC to no

9.4.6 SIM card

circuit diagram:


C8813 SIM card on the soft board, connected through the motherboard connector interface

provides signal input and output is controlled by the PM8029.

failure analysis process:

Symptom: UIM card is not recognized

Solution: First check the UIM deck is normal,

Do not read the UIM card

Replace the UIM card Y end

After normal?

N

Check the UIM card N Welding or replacement

UIM card Block is normal?

Y

Check VDD_SIM? N Check VDD_SIM

Normal?

Y

Deboot repare


After level conversion by PM8029 for the MPP pins to communicate with the SIM card.

VREG_L16_UIM1 voltage can be set to 1.5 ~ 3.05V. USIM interface general operating level of 1.8V or

3.0V. The following table

USIM level for the PM8029's conversion interface:

MSM and the interface signals Level USIM card and interface signals level

UIM1_RESET VREG_L16_UIM1 UIM1_MSM_CLK VREG_S3 UIM1_CLK configured by s.ware UIM1_MSM_DATA UIM1_DATA

Note: Due to the number of user actions SIM card number, so the increase TVS tube, providing static

and surge protection.

9.4.7 IO Interface

circuit diagram:


IO interface to connect the charger when the charger provided VCHG charging voltage for battery

charging; When connecting cable,

USB_HS_DN and USB_HS_DP phone for communications and computer (for software upgrades, read

the phone information, etc.).


Symptom: not charging, I / O interfaces nowhere

Treatment: Clean, plus welding or replacement interfaces



VCHG charging high power input, 5V

USB_DM digital signal without

USB_DP digital signal without

9.4.8 SD Card Interface

Circuit diagram:


Plus U1402 for ESD and EMI filtering.


Symptom: does not know the card, no card reader

Treatment:

Do not read Micro-SD card

After replacing the card is Y Do not read Micro-

Normal? SD card

N

U1402 both sides of the signal N Re-welding U1402

Are conduction?

Y

Update software verification is Y END

No normal?

N

Deboot repare

9.4.9 FM + BT

circuit diagram:

BT FM Principle Analysis:

C8813's design, using BT, FM combo modules to achieve its function, using Qualcomm's WCN2243

achieved.

In this design as a separate BT antenna, FM antenna to the headphone left and right channels.

MSM8625 provides PCM and UART interfaces directly connected with the PCM, UART signal BT

module interface signals given

Defined as follows:

MSM8625A signal line definitions

GPIO_44 UART1_CTS_N sent to the slave master's ready to receive

GPIO_43 UART1_RFR_N from the machine to the host issued clear to

send

GPIO_46 UART1_TX send signals

GPIO_45 UART1_RX received signal

GPIO_69 AUX_PCM_DIN PCM input

GPIO_68 AUX_PCM_DOUT PCM output

GPIO_70 AUX_PCM_SYNC PCM synchronization

GPIO_71 AUX_PCM_CLK PCM clock

GPIO_107 MSM_WAKES_BT wake up the host

GPIO_83 BT_WAKES_MSM ake BT

PM8029 provides audio input interface, directly connected with the left and right channel signals FM

module interface signals are defined as follows:

WCN2243 network MSM8625 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 LINE_IN_RM FM OUTPUT

PM8029


Symptom: FM does not work

Treatment: If you can find a signal, but no sound, check the headset

pathway.

No Signal FM

FM silent

FM station search result is not satisfactory

After replacing the normal headphones

Normal? Y end

N

Check the seat re-welding headphones

After normal? Y end

N

After updating the software is

Normal? Y end

N

Deboot repare

Chapter 10 of the PCB and BGA chip solder indication map

Red (R: 255, G: 0, B: 0): Empty Point

Green (R: 0, G: 255, B: 0): ground

Blue (R: 0, G: 0, B: 255): solder

TOP：

BOTTOM：

U201：

U401：

U1800

U3901：

U901：

U1402：

U6301：

U6100：

U6000:

U1205：

U1002：

C8813 Service Manual

Documents

diagram chapter

information chapter

directory chapter

step chapter

sd card interface

voice test chapter

sd upgrade

fm bt chapter