texet X-Navi User manual

TEXET X-Navi
Smartphone
Service Manual
(This document is only for reference)
CONTENTS
• Specifications
• Safty Precautions
• Product Function
• Block Diagrams
• Chart of Troubleshooting
• PCB Diagrams
• SCH Diagrams

Specification
General Specification
GSM850
EGSM900
DCS1800
PCS1900
WCDMA1900
WCDMA850
Freq.Band[MHz]
Uplink/Downlink
824-894MHz
880-960MHz
1710-1880MH
z
1850-1990MH
z
1850~1910
1930~1990
824~849
869~894
ARFCN range
128~251
0~124 &
975~1023
512~885
512~810
9262-9538
9662~9938
4132-4357
4357~4458
Tx/Rx spacing
45MHz
45 MHz
95 MHz
90MHz
80 MHz
45 MHz
Modulation
0.3GMSK
0.3GMSK
0.3 GMSK
0.3GMSK
BPSK
BPSK
MS Power
<33dBm
<33dBm
<30 dBm
<30 dBm
<24dBm
<24dBm
Power Class
4
4
3
3
3
3
Cell Radius
35Km
35 Km
2 Km
2 Km
800m
1Km
Safety Precautions
Repair Precaution
● Repair in Shield Box, during detailed tuning.
Take specially care of tuning or test, because specificity of cellular phone is sensitive for
surrounding interference(RF noise).
● Be careful to use a kind of magnetic object or tool, because performance of parts is
damaged by the influence of magnetic force.
● Be surely use a standard screwdriver when you disassemble this product, otherwise
screw will be worn away.
● Use a thicken twisted wire when you measure level.
A thicken twisted wire has low resistance, therefore error of measurement is few.
● Repair after separate Test Pack and Set because for short danger (for
example an overcurrent and furious flames of parts etc.) when you repair
board in condition of connecting Test Pack and tuning on.
● Take specially care of soldering, because Land of PCB is small and weak in heat.
● Surely tune on/off while using AC power plug, because a repair of battery charger is
dangerous when tuning ON/OFF PBA and Connector after disassembling charger.
●Don't use as you pleases after change other material than replacement registered on
SEC System. Otherwise engineer in charge isn't charged with problem that you don't keep
this rules.
ESD(Electrostatically Sensitive Devices)
Precaution
Several semiconductors may be damaged easily by static electricity. Such parts are called
by ESD (Electrostatically Sensitive Devices), for example IC,BGA chip etc.
Read Precaution below, You can prevent from ESD damage by static electricity.

● Remove static electricity remained your body before you touch semiconductor or parts
with semiconductor. There are ways that you touch an earthed place or wear static
electricity prevention string on wrist.
● Use earthed soldering steel when you connect or disconnect ESD.
● Use soldering removing tool to break static electricity. Otherwise ESD will be damaged
by static electricity.
● Don’t unpack until you set up ESD on product. Because most of ESD are packed by box
and aluminum plate to have conductive power, they are prevented from static electricity.
● You must maintain electric contact between ESD and place due to be set upuntil ESD is
connected completely to the proper place or a circuit board.
Product Function
• Smartphone, 1.2GHz CPU
• Android 4.2
• 4.5” WVGA LCD with CTP
• 32 GB (4GB) EMMC+4GB (512GB) DDR2
• 2G Dual band (GSM900/DCS1800) + WCDMA900/1900/2100
• Camera and Video with Flash LED
• Music player
• Speaker
• Calendar
• Web browser
• Dual SIM Card
• T-flash Card Up to 32GB
• BT& FM& WIFI&GPS
• 3D accelerator sensor
• USB2.0

Block Diagrams

Chart of Troubleshooting
1、Base band
1.1、Cannot download
Cannot download (No DA Process)
Check the connection between Download Cable and handset.
Connect again and check whether it is OK or not.
Check the USB connector and try change the USB connector.
Check the power supply and the output of U301 Change U301 or Re-welding it
Check the X600 output of U600 Change U600 or Re-welding it
Check the 32.768 crystal output of U101 Change U101 or Re-welding it
Check the welding Both U101 and U402 Change or Re-welding them
Cannot download (Have DA Process, But have no RB or FR or DL process)
Check the connection between Download Cable and handset. Connect
again and check whether it is OK or not. If possible, try to change
Download PC etc. to ensure fault from handset
Try select Type in “Download tool” as “For and Download All” to Change or Re-welding
download. Caution: Only these types of failure try this step
don’t use U402 or U101 for any other failures.
Try to re-calibration the Main PCBA or Use Meta to write the RF
parameter, and then use “SN STATION” to re-write IMEI. End

1.2、Cannot power-on
Cannot power-on
Check if it can be power on after re-downloading (Follow 1.1)
Check the Battery connector and the on/off switch
Check the power supply and the output of U301 Change or Re-welding U301
Check the X600 output of U600 Change U600 or Re-welding it
Check the 32.768 crystal output of crystal Change or Re-welding U101
Check the welding U101or U402 Change or Re-welding them
1.3、No Ring
Setting rightly and Check SPK
Check the speaker and it contacts with on the Main PCBA. Change or re-welding the SPK
Check U1402 and the components around it Change or re-welding them
Check the AU_HPL and AUDIOEN signal (High) from U301 Change or re-welding U301
End

1.4、No vibration
Setting right and check Motor
Check VIBR_PMU_OUT signal from U301 Change or re-welding U301
End
1.5、The abnormality of the side-key operation
Abnormality of side-key
Check side-key
Check U101 Change or re-welding it
End
1.6、The abnormality of speech
Abnormality of speech
Receiver no sound MIC not working Earphone no working
Check receiver and the Check MIC and the Check Earphone and the
components around it components around it components around it
Check HP_MIC signal Check U101,
Try to re-welding or change it (low level) from U101
End

1.7、Camera problem
Camera problem
Check or change Camera, check J840 and the Components around it.
Check VCAMA_PMU, VCAMD_PMU, VCAM_IOPMU, Re-welding or change U301
VCAM AFPMU from U301
Check and try to change or re-welding U101
End
1.8、LCD display problem
LCD no display (have backlight, white screen) LCD no display (have no
Backlight, black screen)
Check or change LCD and check CON804 Check or change LCD, check U801 and the
Components around it.
Check and try to change or re-welding U101
End
1.9、Charge failure
Charge failure
Check CON301 Re-welding or change CON301
Check VCDT, CHR_LDO, VDRV, ISENSE from U301 Re-welding or change U301
Check U302 and the components around it. Try to re-welding or change them
End

1.10、CTP(Touch Panel) failure
CTP failure
Check or try to change CTP, check TP_1.8V and TP_2.8V
power supply from U301, check CON880 and components around it. Re-welding or change U301
Check or try to re-welding or change U201
OK
1.11、SIM card failure
SIM failure
Check VSIM1_PMU and VSIM2_PMU power supply from U301 Re-welding or change U301
Check SIM1 or SIM2 and the components around it. Re-welding or change them
Check or try to re-welding or change U201
End
1.12、T-Flash card failure
T-Flash card failure
Check VMCH power supply from U301 Re-welding or change U301
Check or try to re-welding or change CON1502 or U101
End

1.13、BT/WIFI problem
BT/WIFI Failure
Check antenna contact withANT1003 and ANT1004.
Check U1000 and the components around it
Re-welding or change them
End
1.14、GPS problem
GPS Failure
check antenna contact withANT1003 and ANT1004
Check U1006 and the components around it Re-welding or change it
Check U1000 and the components around it
Re-welding or change them
End
1.15、FM problem
FM Failure
check earphone connect with CON401 is OK.
Check U1000 Re-welding or change it
Check and try to re-welding or change U101, U301.

End
2、RF parts
2.1、2G RX failure
2G Dual band RX failure
check the antenna contact with shrapnel
try to Re-welding or Check all control signals of Check the RX output signal
change U701 U701: PAEN, BANDSW, and from Z600
MODE_PA
Re-welding or change Z600
Check U600 and the components
around it.
Check or try to change U600 and U101
End
2.2、2G TX failure
2G TX failure
check the antenna contact with shrapnel
Try to Re-welding or Check all control signals of Re-welding or change
Change U701 U701: PAEN, BANDSW, and U600
MODE_PA
Re-welding or change U101
End
2.3、3G TX/RX failure

3G TX failure
Check U701 and the components around it Re-welding or change U701
Check U602,U604 and the components around them Re-welding or change them
Check U706,U709 and the components around them Re-welding or change them
Check U600 and the components around it Re-welding or change U600
Re-welding or change U101
End