- 51 -
4. TROUBLE SHOOTING
4. TROUBLE SHOOTING
4.1 Power Supply Failure
Figure 4-1.
4. TROUBLE SHOOTING
- 52 -
4.2 RX Sensitivity Trouble (EGSM)
Figure 4-2. RX Sensitivity Trouble (EGSM).
4.3 RX Sensitivity Trouble (DCS)
Figure 4-3. RX Sensitivity Trouble (DCS).
U405 pin 10 RF signal
U405 pin 10 RF signalU405 pin 10 RF signal
U405 pin 10 RF signal
is over -65dBm
is over -65dBmis over -65dBm
is over -65dB
Check U405 and
Check U405 andCheck U405 and
Check U405 and
peripheral circuit
peripheral circuitperipheral circuit
peripheral circuit
YES
YESYES
YES
YES
YESYES
YES
NO
NONO
NO
U405 : ANT. Switch
U405 : ANT. Switch U405 : ANT. Switch
U405 : ANT. Switch
U408 : RF SAW Filter
U408 : RF SAW Filter U408 : RF SAW Filter
U408 : RF SAW Filter
U411 : CX74017
U411 : CX74017 U411 : CX74017
U411 : CX74017
(High Frequenc y Probe)
(High Frequenc y Probe)(High Frequenc y Probe)
(High Frequenc y Probe)
U408 pin 3 RF signal
U408 pin 3 RF signalU408 pin 3 RF signal
U408 pin 3 RF signal
is over -68dBm
is over -68dBm is over -68dBm
is over -68dBm
Check U408
Check U408Check U408
Check U408 and
and and
and
peripheral circuit
peripheral circuitperipheral circuit
peripheral circuit
Rework on Calibration
Rework on CalibrationRework on Calibration
Rework on Calibration
YES
YESYES
YES
NO
NONO
NO
@947.4MHz
@947.4MHz@947.4MHz
@947.4MHz
@947.4MHz
@947.4MHz@947.4MHz
@947.4MHz
START
(62CH, Sector Power - 60dBm)
U401 pin 1 RF signal
U401 pin 1 RF signalU401 pin 1 RF signal
U401 pin 1 RF signal
is over -68dBm
is over -68dBmis over -68dBm
is over -68dBm
Check U401 and
Check U401 andCheck U401 and
Check U401 and
peripheral Circuit
peripheral Circuitperipheral Circuit
peripheral Circuit
YES
YESYES
YES
YES
YESYES
YES
NO
NONO
NO
ANT. Switch
ANT. Switch ANT. Switch
ANT. Switch
U407 : RF SAW Filter
U407 : RF SAW Filter U407 : RF SAW Filter
U407 : RF SAW Filter
U411 : CX74017
U411 : CX74017 U411 : CX74017
U411 : CX74017
(High Frequenc y Probe)
(High Frequenc y Probe)(High Frequenc y Probe)
(High Frequenc y Probe)
U407 pin 3 RF signal
U407 pin 3 RF signalU407 pin 3 RF signal
U407 pin 3 RF signal
is over -71dBm
is over -71dBmis over -71dBm
is over -71dBm
Check U407 and
Check U407 andCheck U407 and
Check U407 and
peripheral Circuit
peripheral Circuitperipheral Circuit
peripheral Circuit
Rework on Calibration
Rework on CalibrationRework on Calibration
Rework on Calibration
YES
YESYES
YES
NO
NONO
NO
@1842.6MHz
@1842.6MHz@1842.6MHz
@1842.6MHz
@1842.6MHz
@1842.6MHz@1842.6MHz
@1842.6MHz
START
(699CH, Sector Power - 60dBm)
4. TROUBLE SHOOTING
- 53 -
4.4 TX Power Trouble
Figure 4-4. TX Power Trouble.
Setup Te st with RFCAL
Setup Te st with RFCALSetup Test with RFCAL
Setup Te st with RFCAL
GSM:62CH, DA C value 600
DCS:700CH, DAC value 700
Power Level: GSM 5, DCS 0
Test DC Voltage :4 V
U105: AD6522 (D ig ital)
U103: AD6521 (An alog)
U409: PAM (PF08107B)
U411: RF Main Chip
(C X74017)
U405: ANT S/W
(LM G002S- 5008C)
U412: APC IC (AD8315)
N401: Directional coupler
(LD C15D190A0007A)
Is the Modul ated Tx s ignal of U409 (GSM:pin1)
about -2 dBm,(DCS pin8) about -2d Bm?
(GSM 902. 4MHz, DCS 1747.8MHz)
Is the amplif ied Tx s ig nal o f U409(GSM:p in4)
about 9.3dBm,(DCS:pin5) about 8.5dBm?
Is the input powe r of U405(GSM:pin5)
about 10dBm,( DCS:pin1) about 9d Bm?
Check or change resistors between U411 and U409
Check the Tx IQ Signal level of U411
(pin20, 21, 22, 23)
(DC1.17V, 0.97V p-p swing s ignal)
Check or c hange U411 o r U103 and peripheral circuit
Is the Modul ated Tx signal of U411 (GSM:pin64)
about 7.5dBm,(DCS:pin1) about 6.5dBm?
(GSM 902.4MHz, DCS 1747.8MHz)
Check or change U411 and peripheral circuit
Is th e o u tput voltage level of U41 2(Vapc:pin7)
about 1.18V?
Change U409
Is the TXEN signal level of U412(ENBL:pin2)
High(over 2.8V)?
Change U105
Change U412
Check ca libration da ta
and c hange U405
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
Is the TXRAMP signal vo ltage of
U412(VSET:pin3) over 1.2V?
Change U103
YES
NO
YES
Check or change N401 and
peripheral circuit .
EGSM
DCS
GSMSEL DCSSELANT S/W TXPA
Truth Table
1 0 1
0 1 1
EGSM
DCS
BANDSEL1 BANDSEL2TRANSCEIVER
Truth Table
0 EGSM
DCS
GSMSELPAM
Truth Table
1
01
0
0
4. TROUBLE SHOOTING
- 54 -
4.5 RX Trouble
START
PIF Power On
RF2.85V
O.K?
RFMain Chip O.K?
Ref. Clock 13MHz O.K?
YesYes
YesYes
U414Check!!
Pin 2
.
>
3.2 V
Pin 1. 2.85V
Y401Check!!
Pin 4. 2.7V
P in 3. 13MHz
U411Check!!
NoNo
NoNo
Yes
Block 2
Block 3
Block 4
Block 6
NoNo
Antenna S/W
RX O.K?
Goto Block 2 Test.
Goto Block 3 Test
Goto Block 4 Test
No
U405Check!!
YesYes
RX Path Working !
RFFilterO.K?
U407, U408Check!!
Block 4
NoNo
Goto Block 5 Test
YesYes
Goto Block 6 Test
Setting : After Initialize Agilent 8960, Test in EGSM or DCS Mode
4. TROUBLE SHOOTING
- 55 -
Block 2 Test ) U414 (RF 2.85V) Check!!
Voltage> 3.2V ?
NoYes
RF 2.85V O.K?
No
Yes
Check Placement of U414
VBAT Line Check Short?(Using Multi Meter)
If it has not problem
Check Placement of U414
Check RF2.85V Line. Short?(Using Multi Meter)
Replace U414
2-B Test!!
U414Work ing
Goto Block3 !!
Pin 6.High ?
Yes
Check U105
No
If it has not problem
U414.1
U414.6
U414.2
2-A) Check Pin 2. Using Oscilloscope
2-B) Check Pin 6. Using Oscilloscope
2-C) Check Pin 1. Using Oscilloscope
4. TROUBLE SHOOTING
- 56 -
Block 3 Test) Y401 (13MHz Oscillator) Check!!
Y401.3
Y401.4
Voltage 2.7V ?
NoYes
13MHz Output ?
No
Yes
Replace U101
Replace Y401
3-C) Test!!
Pin 1.High ? AFC LineShort?
No
13MHz Line Short?
Yes
No
Yes
Check Short
3-C) Test!!
Yes
No
Y401Working
Goto Block 4
U413Working?
U101 Pin 25. 2.7 V?
No
Check Short
3-B) Test!!
Yes
Yes
Replace U103
Replace U413
3-C) Test!!
No
3-A) Check Placement of Y401
3-B) Check Pin 4. Using Oscilloscope.
3-C) Check Pin 3. Using Oscilloscope.
4. TROUBLE SHOOTING
- 57 -
Block 4 Test) U411 (RF Main IC) Check!!
GSM : CH40, -60dbm
DCS : CH700, -60dbm
U411.13
U411.11
4. TROUBLE SHOOTING
- 58 -
Block 4 Test) U411 (RF Main IC) Check!!
4-A) Check Placement of U411
4-B) Check U411 Pin 11, Using Spectrum Analyzer
4-C) Check U411 Pin 13, Using Spectrum Analyzer
-68dBm
-71dBm
(2)
(1)
GSM SAW Filter
Output ~ -68dbm ?
5-A Test!!
No
Yes
U411 Working
Goto Block 5
DCS SAW Filter
Output ~ -71dbm ?
5-A Test!!
No
Yes
4. TROUBLE SHOOTING
- 59 -
Block 5 Test) U408(GSM Filter), U407(DCS Filter) Check!!
GSM : CH40, -60dbm
DCS : CH700, -60dbm
5-A) Check Placement of U408, U407
5-B) Check U408 Pin 1, 3 Using Spectrum Analyzer
5-C) Check U407 Pin 1,3 Using Spectrum Analyzer.
NoYes
Check Soldering
Replace U408
5-B) Test!!
RF Output
Pin 1 ~ -65dbm ?
Pin 3 ~ -68dbm ??
GSM BAND PASS FILTER
RF Output
Pin 1 ~ -68dbm ?
Pin 3 ~ -71dbm ?
No
Yes
Replace U407
5-C) Test!!
Goto Block 6 !
DCS BAND PASS FILTER
U407.1
U407.3
U408.1
U408.3
- 60 -
4. TROUBLE SHOOTING
Block 6 Test) U405 (RX ANT Switch) Check!!
GSM : CH40, -60dbm
DCS : CH700, -60dbm
6-A) Check Placement of U405
6-B) Check SW401(Mobile Switch) Pin 1,2 (RF Signal Line) Using Spectrum Analyzer
6-C) Check U405 Pin 10, 1 Using Spectrum Analyzer.
No
Yes
Check Soldering
Replace SW401
6-B) Test!!
RF Output ?
RF Output
Pin 10 ~ -65dbm ?
Pin 1 ~ -68dbm ??
No
Yes
Replace U405
6-C) Test!!
RX Path Working !
SW401.1
SW401.2
U405.10
U405.1
- 61 -
4. TROUBLE SHOOTING
4.6 TX Trouble
Setting : After Initialize Agilent 8960, Test in EGSM or DCS Mode
PIF Power On, Te
Block 7
Block 8
Block 9
Block 11
Dictional Coupler
Antena Part TX O.K.?
START
TXIQ O.K.?
YesYes
PAM O.K.?
YesYes
O.K.?
YesYes
YesYes
st after Call112
U411Check!!
U409Check!!
N401Check!!
U405Check!!
NoNo
NoNo
NoNo
NoNo
Goto Block 7 Test
Goto Block 8 Test
Goto Block 9 Test
Goto Block10Test
TX Path Working !
- 62 -
4. TROUBLE SHOOTING
Block 7 Test) U411 (TXIQ) Check!!
GSM : CH62, DAC Value 560
DCS : CH700, DAC Value 560
7-A) Check Pin 20(TXIP) & Pin 21(TXIN), Pin 22(TXQP) & Pin 23(TXQN) Using Oscilloscope
Reference TXIQ Signal
U103 is Not Working
Replace U103
No
4 P in ALL
High Output ?
No
Just Pin 1,2 or 3
High Output ?
TXIQ Li ne Short ?
No
Check Short
Block 7)Test!!
Yes
Yes
Yes
Goto Blo ck 8 !!
U411.20
U411.21
U411.22
U411.23
- 63 -
4. TROUBLE SHOOTING
Block 8 Test) U409 (PAM) Check!!
GSM : CH62, DAC Value 560
DCS : CH700, DAC Value 560
8-A) Check Placement of U409
8-B) Check Pin 3,6 Using Oscilloscope 8-B) Check Pin 3,6 Using Oscilloscope
8-C) Check Pin 4 Using Spectrum Analyzer 8-C) Check Pin 5 Using Spectrum Analyzer.
GSM TX BAND
DCS TX BAND
Voltage > 3.2V ?
No
Voltage > 3.2V ?
Yes YesNo
Check Main Battery
TX Output ~18dbm?
Yes No YesNo
Attenuator Check!!
Check Short & Resistor Value
8-B) Test!!
Each Power
Level OK.?
No
Yes
Yes
No
Each Power
Level OK. ?
Block 9 !!
Block 8!!
TX Output ~20dbm?
U409.4
U409.5 U409.6
U409.3
- 64 -
4. TROUBLE SHOOTING
Block 9 Test) N401 (Dual Band Coupler) Check!!
GSM : CH62, DAC Value 560
DCS : CH700, DAC Value 560
9-A) Check Placement of N401
9-B) Check N401 Pin 1, Using Spectrum Analyzer 9-B) Check N401 Pin 3, Using Spectrum Analyzer
GSM TX BAND
DCS TX BAND
RF Output ~ 20dbm?
Yes No YesNo
No Yes No
Replace N401
9-B)Test!!
9-B) Test!!
C412 Valid?
(Short& Open)
C414 Valid?
(Short& Open)
Goto Block 10!
RF Output ~ 18dbm?
Yes
N401.3 N401.1
- 65 -
4. TROUBLE SHOOTING
Block 10 Test) U405 (/TX ANT Switch) Check!!
GSM : CH62, DAC Value 560
DCS : CH700, DAC Value 560
10-A) Check Placement of U405
10-B) Check SW401(Mobile Switch) Pin 1,2 (RF Signal Line) Using Spectrum Analyzer
10-C) Check U405 Pin 5, 3 Using Spectrum Analyzer.
No
Yes
Check Soldering
Replace SW401
10
-B) Test!!
RF Output ?
RF Output
Pin 5~ 10dbm?
Pin 3~ 9dbm ?
No
Yes
Replace U405
10-C) Test!!
TX Path Working !
SW401.1 SW401.2
U405.3 U405.5
- 66 -
4. TROUBLE SHOOTING
4.7 Power on Trouble
- 67 -
4. TROUBLE SHOOTING
4.8 Chage Trouble
- 68 -
4. TROUBLE SHOOTING
4.9 LCD Trouble
START
PIF Power On, Test after Call112
LCD Driver
Source Voltage ?
YesYe s
U101 Check! !
NoNo
Block 16
Goto Block 16Test
Cont act of LCD module
with LCD connector on
PCB OK.?
YesYe s
NoNo
Reassemble LCD module
With LCD co nnector
Check Soldering
YesYe s
NoNo
Goto Block 17Test
LCD Working !
Block 1 7
CN301 Check!!
Setting : After Initialize Agilent 8960, Test in EGSM or DCS Mode
- 69 -
4. TROUBLE SHOOTING
Block 16 Test) CN301 Check!!
16-B) Check CN301 Pin 29, 20, 1 Using Osciolloscope
16-A) Check Placement of CN301
NoYes
Check U101
&
Line Path
16-B) Test!!
Pin 29 > 2.45V?
Pin 20
> 3.2V ?
Pin 1
> 2 .8V ?
Goto Block 17!
Yes
Replace
U101
Pin 20
Pin 1 Pin 29
Soldering Check
in LCD Module
PMIC(U101)
CN301
4. TROUBLE SHOOTING
- 70 -
Block 17 Test) CN302 Check!!
17-A) Check Placement of CN302
17-B) Check CN 302 Soldering & Line Path
Reference LCD Signal
4. TROUBLE SHOOTING
- 71 -
4.10 RECEIVER Trouble
Setting : After Initialize Agilent 8960, Test in EGSM or DCS Mode
PIF Power On, Test afte r Call 112
START
Block 14
Detect Signal Level.?
YesYes
Block 15
Ch eck Soldering
YesYes
RECEIVER Working !
U202Check!!
C206, Receiver Chec k!!
NoNo
Goto Bloc k 14Test
4. TROUBLE SHOOTING
- 72 -
4.11 Speaker Trouble
4. TROUBLE SHOOTING
- 73 -
4. TROUBLE SHOOTING
- 74 -
4.12 MIC Trouble
START
PIF Power On, Test a
fter Call 112
2V45_VAN O.K.?
Audio Signal Level O.K.?
Check MIC Soldering
YesYes
YesYes
YesYes
R108Check!!
C129, C132 Check!!
NoNo
NoNo
Block 12
Block 13
Goto Block12Test
Goto Block13 Test
MIC1Check!!
MI C Working !
Setting : After Initialize Agilent 8960, Test in EGSM or DCS Mode
4. TROUBLE SHOOTING
- 75 -
Block 12 Test) MIC101 (MIC) Check!!
12-A) Check Placement of MIC101
12-B) Check R108 Using Osciolloscope
NoYes
Check U101
&
Soldering
R108, R105
12-B) Test!!
2.5 V ?
Goto Block 13!
C132
MIC101
C129
R108 R105
PMIC(U101)
- 76 -
4. TROUBLE SHOOTING
Block 13 Test) MIC101 (MIC) Check!!
13-A) Check Audio Signal Level C129, C132 After putting audio signal in MIC
Reference MIC Signal
No
Yes
Check Soldering
Replace C129, C132
13-1) Test!!
A few hundreds of mV Signal
are measured ?
MIC Working !
- 77 -
4. TROUBLE SHOOTING
Block 14 Test) U212 Check!!
14-A) Check Placement of RECEIVER
14-B) Check 202 Pin4 Using Osciolloscope
Reference RECEIVER Signal
C206
U202.4
PMIC(U101)
RECEIVER
YMU762(U203)
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