Turbo+ Maintenance Manual
Service Manual
目录
1 V131 Module Features 3
1.1 V131 3
1.2 Basic Feature 3
1.3 Typical Application 3
2 Main board explored overview 5
3．Detailed Function Circuit 7
3.1 Download Module 7
3.2 Audio Module 7
3.2.1 Micphone Circuit 7
3.2.2 Receiver Circuit 8
3.2.3 Speaker Circuit 8
3.3 FM Module 8
3.4 BT & WIFI Module 10
3.5 RF Module 11
3.6 LCM Module 13
3.7 CAMERA Module 14
3.8 KEYAPD Interface 15
4 Fault Maintenance 16
4.1 RF Part 16
4.2 BB Part 16
1 V131 Module Features
1.1 V131
Figure 1.1: V131 Module
1.2 Basic Feature
Table 1-1: Feature
Platform / Spreadtrum SC7731Band / GSM900/DCS1800/ WCDMA BandⅠ
LCM
CAMERA
MCP Module / EMMC flash
BT&WIFI Module / SR2351
FM RX Module / SR2351
Audio PA / Built-in (CLASS D)
SIM / Dual SIM
I/O / MICRO USB 5PIN
Torch / Support
Keypad / 3 Key
1.3 Typical Application
Figure 1.2: Typical Application with SC7731 Based platform
2 Main board explored overview
Figure 2.1: top
Figure 2.2: bottom
3．Detailed Function Circuit
3.1 Download Module
Download through USB port and OK key, program select download mode, when connect BOOT(pin U1TXD) to GND.
Figure 3.1: V131 D/L Interface
3.2 Audio Module
3.2.1 Micphone Circuit
Figure 3.2: Micphone
If MICPHONE useless ,firstly you should check B0507/B0508 ok or not, use multimeter measure connect or not ,if not connect that indicate not good.
3.2.2 Receiver Circuit
Figure 3.3: Receiver
The receiver is part with audio output,if receiver defet,it caused by B0557/B0558.should measure these two parts ok or not
3.2.3 Speaker Circuit
Internal AudiO PA(Class D) ,this module use Bulit-in.
If speaker volume issue. firstly check speaker and B0547,B0548 then check baseband IC
Figure 3.4: Speaker
3.3 FM Module
FM Receive function use SR2351 chipset.
Figure 3.5
FM radio is a basic functions of cell phone, Spreadtrum SC7731 platform-- the main FM functions are integrated inside the SR2351 chip, FM failures are generally: FM no sound, no station, FM station less, the above chips is generally caused by bad SR2351, use the function must insert the headset antenna, the function to work properly.
3.4 BT & WIFI Module
Figure 3.6
Bluetooth poor performance of the function, not active ,not find Bluetooth, next to match the circuit in normal circumstances, poor Bluetooth antenna, crystal and 26 trillion can lead to poor.
3.5 RF Module
RF PA, type HS8684, item U0680.Saw Filter(GSM/DCS), item U0641 and 0604. RF PA(WCDMA/HSDPA/HSUPA/-BAND I), type VC5341, item U0660. RF Transceiver, type SR3131, item U0600.
Figure 3.7: RF Front-end Module
RF PA is the probability of the most original failure, common faults are: no network, no signal, the signal is weak, can dial emergency calls, etc., first replace the PA amplifier, verify failure existence or not , PA front-end RF signal head can lead to bad signal
RF TRANSCEIVER，type SR3131，item U0600。
Figure 3.8: RF TRANSCEIVER
The IF part is to control the RF signal input / output of the important part, it is important part include receive filter, IF chip, clock crystal 26, common faults: no network, no signal, the signal is weak, can dial the emergency phone, the crystal 26 trillion higher probability of bad, bad failures related to the RF part of the main CPU chip also will lead to.
3.6 LCM Module
Figure 3.9: LCM
The LCM connector is mounted on the motherboard, and the LCM should be well plugged in the connector.
3.7 CAMERA Module
Figure 3.10: CAMERA
The camera connector is mounted on the motherboard, and the camera should be well plugged in the connector.
3.8 KEYAPD Interface
Figure 3.11: KEYAPD
4 Fault Maintenance
4.1 RF Part
Refer to function circuit Part 3.5.
4.2 BB Part
Refer to function circuit.
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