cromax X458 User manual

X458 L3 Service Manual
1
All manuals and user guides at all-guides.com
all-guides.com

X458 L3 Service Manual
2
CAUTIONS
1、Please read this service manual carefully and make sure all elements of anti-static are in place before the
repair work is carried out.
2、Servicing and alignment MUST be undertaken by qualified personnel only.
3、Please use specified tools and equipments for servicing, in which the parameters need to be calibrated with
specified criteria.
Content
1. Brief Introduction….………………………………………………………………………………….3
2. Exploded View……………………………………………………………………………………….4
3. Tools……………………………………………………………………………………………………5
4. Assemble & Dissemble
Dissembly..................…………………………………………………………………………...6～8
Assembly………………………………………………………………………………………..9～11
5. Picture of main board
A&B side of PCBA .…………….…………………………………………………….………..12
A&B of PCBA Layout………….….………….…………………………….……………………..13
6. System Block Chart………………………………………………………………………………...14
7. Unit Circuit Map ………………………………………………………………………..….......16～21
8. Trouble Shooting Guide ……..…………………………………………………………….... 22～27
9. Upgrading & IMEI writing………………………………………………………………...……...28～36
10. CIT testing…………………………………………………………………………………… ……...37
All manuals and user guides at all-guides.com

X458 L3 Service Manual
3
Chapter 1 Specification
Specification :
Network: 850/900/1800/1900MHz
Display: 3.5“ HVGA 320*480
Camera: VGA(1.3M by Software)
BT:3.0
Memory: 64M+128M
Lithium Battery: Standard (1050mAh)
USB Data cable: USB 1.1
Features & Functions
Dual SIM Dual Standby Single working
Full touch
FM
Multi-Media application
0.3MP with sw upgarde to 1.3MP
T-Flash（Support 8G T Card）
3.5“ HVGA 320*480
MP3、MP4、AVI 、3GP
USB1.1，Mini USB
All manuals and user guides at all-guides.com

X458 L3 Service Manual
4
Chapter 2 Exploded View
All manuals and user guides at all-guides.com

X458 L3 Service Manual
5
Chapter 3 Tools
Power Supply
Multimeter
Solder iron
Hot Air Gun
Solder wire, Flux
PC, Download cable
Others
Pick
Screw
Driver
Tweezer
Wrist
grounding
strap
Antistatic
gloves
Cable
All manuals and user guides at all-guides.com

X458 L3 Service Manual
6
Chapter 4 Disassembly & Assembly
1. Disassembly Process
1. Remove the battery cover
2. Unfasten the 4 screws by screw driver
4. Unfasten the 2 screws by screw driver.
5. Remove the TP connector.
3. Prize up the back cover
6. Stick protection film for front cover.
.
All manuals and user guides at all-guides.com
all-guides.com

X458 L3 Service Manual
7
Finished.
7. Remove the TP
8. Remove the LCD by electric soldering iron
All manuals and user guides at all-guides.com

X458 L3 Service Manual
8
2. Assembly Process
Finished.
4. Fasten the 2 screws..
3. Install the PCBA.
1. Install the TP
2. Install the LCD by electric soldering iron
6. Fasten the 4 screws..
5. Install the back cover.
All manuals and user guides at all-guides.com

X458 L3 Service Manual
9
Chapter 5 Picture of PCBA
5.1 Side A
PCBA (Side A) Location of components
5.2 Side B
PCBA (Side B) Location of Components
(J201)battery
conector
I/O connector
U101
CPU
U800 wifi
chip
Mic
Camera
connector
U301
26MHZ
LCD
Connector
(U302)
RF PA
(U401)
FLASH
(J401)
Audio jack
All manuals and user guides at all-guides.com

X458 L3 Service Manual
10
5.3 PCBA Layout side A
5.4 PCB Layout Side B
All manuals and user guides at all-guides.com

X458 L3 Service Manual
11
Chapter 6 System Block Chart
All manuals and user guides at all-guides.com
all-guides.com

X458 L3 Service Manual
12
Chapter 7 Circuit diagram for each unit
Data Transfer
Interface
Keypad Interface
Audio Processing
SIM Data
Transfer control
T- T-flash Data
transfer control
All manuals and user guides at all-guides.com

X458 L3 Service Manual
13
All manuals and user guides at all-guides.com

X458 L3 Service Manual
14
Output of SIM Card
All manuals and user guides at all-guides.com

X458 L3 Service Manual
15
CPU POWER SUPPLY OUTPUT PORT
All manuals and user guides at all-guides.com

X458 L3 Service Manual
16
I/O Interface (5PIN)
PA
All manuals and user guides at all-guides.com
all-guides.com

X458 L3 Service Manual
17
Display interface
All manuals and user guides at all-guides.com

X458 L3 Service Manual
18
Chapter 8 Trouble shooting guide
Can’t Download
NO
Replace or
re-solder the I/O
connector
Check power management and
LDO, whether have normal
voltage output or open circuit
Cannot download
Check if it is caused by the
PC, cable, tools etc.
Power on
NO
NO
NO
NO
YES
YES
YES
No
YES
OK
Replace or re-config.
Check I/O Connector
Connect the cable, check if
the current is normal (about
30 mA)
Disconnect the cable
and check if the chipset
is over heat.
Check VCORE、VDD、
VADD、VTCXO、VRTC、
VMEM、26MHZ、
32KHcrystal
Replace U101 MT6260
All manuals and user guides at all-guides.com

X458 L3 Service Manual
19
Cannot power on-current swing instability
YES
NO
NO
YES
YES
NO
YES
NO
NO
NO
NO
26MHZ Check and
replace system
clock：26MHz
Make the phone connect the power
supply and find the current swing at
50-100mA
END
Check the power manage
supply output：
VCCRE 1.8V
VDD 2.8V
AVDD 2.8V
VTCXO 2.8V
VMEM 2.8V
VRTC 1.2V
Replace U101
MT6260
Upgrade the
software
Check and
replace the I/O
connector
Replace or reweld
flash
Replace or
reweld CPU
All manuals and user guides at all-guides.com

X458 L3 Service Manual
20
Cannot power on-low or no current
YES
YES
YES
NO
Clean ，
reweld or
replace it
END
Upgrade the software
Check and
replace I/O
connector
Replace or reweld
flash
26MHZ
Check and replace
system clock：
26MHz
Check the power manage
supply output：
VCCRE 1.8V
VDD 2.8V
AVDD 2.8V
VTCXO 2.8V
VMEM 2.8V
VRTC 1.2V
Replace or
reweld
CPU
Replace U101
MT6260
Make the phone connect the
power supply and find low or no
current
Check the battery
connector and power
key
NO
NO
YES
YES
NO
NO
NO
YES
NO
NO
All manuals and user guides at all-guides.com