E150 Trouble- shooting guide
E150 Trouble-shooting
Guide for Common
Problems
2010. August
Confidential Internal use only
E150 Trouble- shooting guide
Content
1. Description for Circuit Diagram
2. Attentions for dealing with troubles
3. Common troubles
3.1 Abnormal receiving signal & sending signal
3.2 Loosing signal during calling
3.3 Unable to power on
3.4 Keypad no function
3.5 No ring sound during power on
Attachment: picture of PCBA and related indications.
Confidential Internal use only
E150 Trouble- shooting guide
SIM card
LCD bonding
Yamaha
CPU
26M
RF IC
RF
Amplifie
Flash
Confidential Internal use only
E150 Trouble- shooting guide
r
r
r
r
T-flash card
holde
Camera
connecto
USB
connector
Battery
connecto
BT IC
FM
Earphone
connecto
RF test
connect
Confidential Internal use only
E150 Trouble- shooting guide
1. Description for Circuit Diagram
Below is the reference for RF part.
2. Attentions for dealing with troubles
Basic repair process flow is:
receiving PCBAÆ Verify problems Æ Get analysis data from verification and
measurementÆ Analyze possibility of problems from dataÆ Use exclusive method or
checking from simple to complicate cause to rule out all possibilities
Normally, first need to rule out possibilities of external components and then PCBA
possibility.
Confidential Internal use only
E150 Trouble- shooting guide
3. Common troubles
3.1 Abnormal receiving signal & sending signal
When there is no signal or weak signal on handset, then it means receiving signal of
handset has problem.
Firstly, we need to move out the antenna problem. Check assembly of antenna to
make sure whether it is well connected or not: 1. antenna connecting points are well
connected with PCB or not; 2. disassemble the antenna and check whether connection
area on PCB is clean or not. If not clean, please wipe it with alcohol.
Then, after antenna problem is moved out, then we can test PCB directly to verify this
problem. Normally it could be soldering problem of components about RF part. We
can check soldering status or adding bonding to make sure the root cause.
3.2 Unable to power on
This kind of problem is a common problem. Firstly, we should check battery and
battery connection. Check whether there is dirty or not at battery connector pad or
battery connector on PCBA. Secondly, check whether there is short circuit or not and
whether there is current or not when power on. This is normally CPU problem. If
power on sound could be heard or keypad light is on, then need to check soldering
status for LCD.
3.3 LCD issue
Check LCD soldering status first. Adding bonding if needed. If still there is problem,
check the soldering pins whether it is short circuit.
3.4 Keypad no function
Normally keypad no function problem is caused by below: dirt on DOM, keypad
position shifting, or loosing elasticity. Nor mally this kind of problem is on single key
or some keys.
If all keys have no function, please check CPU. But sometime it may due to elasticity
problem of keypad.
Confidential Internal use only
E150 Trouble- shooting guide
3.5 No ring sound during power on
If there is no sound when power on and playing music, then it means audio part has
problem. Firstly, we can replace with new loudspeaker. If still problem, then it should
be PCBA problem.
If there is some sound during power on or playing music, or sometimes automatically
power off, then it should be audio amplifier problem. If not, then it should be problem
on its input/ output control circuit.
Confidential Internal use only
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