LG Nexus 5 Service Manual

3. TROUBLE SHOOTING
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3.16 Proximity Sensor on/off troubleshooting
Proximity Sensor is worked as below:
Call Button click -> Phone number click -> Call connected -> Move objects in front of the sensor-> Control automatically 
the screen’s on/off operation
Check TP11002
Yes
Yes
Yes
START
LCD off?
Change the U11002
Is the function normal operation?
Change the Proxi/light  
Sensor IC...

3. TROUBLE SHOOTING
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< Proximity/Light Sensor >
< Main PCB _Top >
U11002 (APDS9930)
Proximity Sensor
TP11002
ZD11002
EDTY0012501 UCLAMP3311TTP11002
R11003DNI
+1V8_VREG_LVS1
ZD11001
EDTY0012501
UCLAMP3311T
U11002
EAN62568201
APDS-9930-200
9
3
5
4 6 7
2 8
1
SDAVDD
INTSCL
GND
LEDKLEDA
LDR
NCC11007
2.2u
+3V0_VREG_L17
R11011
22
SENSOR2_I2C_SDA
SENSOR2_I2C_SCLPROXIMITY_INT
[Check supply...

3. TROUBLE SHOOTING
- 173 -Copyright © 2013 LG Electronics. Inc. All right reserved.Only for training and service purposesLGE Internal Use Only
3.17 Light Sensor on/off trouble
Light Sensor is worked as below:
Menu Key click -> Settings click -> Display click -> Brightness click -> Automatic brightness click
Check the Pad of TP1(C11007), 3V
Yes
Yes
Yes
START
Changing Brightness?
Check the pad of TP2 (R11003),  
Proximity int
Is the function normal operation?
Change the Proxi/light  
Sensor IC (U11002)...

3. TROUBLE SHOOTING
- 174 -Copyright © 2013 LG Electronics. Inc. All right reserved.Only for training and service purposesLGE Internal Use Only
< Main PCB _Top >
U11002 (APDS9930)
Proximity Sensor
TP11002
Check 3V(C11007)
Proximity_INT(R11003)
< Proximity/Light Sensor >
ZD11002
EDTY0012501 UCLAMP3311TTP11002
R11003DNI
+1V8_VREG_LVS1
ZD11001
EDTY0012501
UCLAMP3311T
U11002
EAN62568201
APDS-9930-200
9
3
5
4 6 7
2 8
1
SDAVDD
INTSCL
GND
LEDKLEDA
LDR
NCC11007
2.2u
+3V0_VREG_L17
R11011
22
SENSOR2_I2C_SDA...

3. TROUBLE SHOOTING
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3.18 NFC 
3.18.1 NFC components
Reference No.DescriptionReference No.Description
U15004BCM20793M, NFC ICX15000Crystal
1
4
A
B C
D
E
F G
TP15004
R15040
TP15007
C15028
U15004
R15028
R15029
C15030
R1503
3
C15041
R15031
TP15002TP15001X15000
C15039
C15037
C15040
C15038
C15031
C1504 3
C1504 4
C1504
2
TP15000
C15045
L15001
C10006
R15030
C15027
C15032
C15047
R15027...

3. TROUBLE SHOOTING
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3.18.2 NFC Signal Path
NFC Rx / Tx Common Signal Path
1
4
A
B C
D
E
F G
TP15004R15040TP15007
C15028
U15004
R15028
R15029
C15030
R1503
3
C15041
R15031
TP15002TP15001X15000
C15039
C15037
C15040
C15038
C15031
C1504 3
C1504 4
C1504
2
TP15000
C15045
L15001
C10006
R15030
C15027
C15032
C15047
R15027
C15033
L15002
C10005
R15034C15034
C15036
R15038R15039
C15046
R15043...

3. TROUBLE SHOOTING
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START
ANT 15000/15001
Check the Connection
Between antenna and Clip
Replace Antenna in
Battery Cover or Clip
No
Yes
Yes
F_SUB Change
Yes
Check antenna
Matching at C15030/C15036
C15032/15034, R15031/R15034
Check RF Line
Tx / Rx Line
Check The Component
Around Antenna
Check The Component Tx / Rx Line
No
No   

3. TROUBLE SHOOTING
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3.19 Power ON Troubleshooting
The main power source of D821/D821 is provided by 2 chips which are PM8941 and PM8841. Since MSM8974 only 
powers up normally when MSM8974 is properly powered therefore, PM8941 is the actual one to take look at.
Power ON sequence of D821/D821 is below.
1. PM8941 receives a poweron trigger (e.g. KPD_PWR_N press).
2. PM8941 poweron...

3. TROUBLE SHOOTING
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3.19.1 Power ON Troubleshooting (MSM8974)
Battery voltagehigher than 3.3V?Change or charging the BatteryNo
Yes
Check SDRAM(U5000) And eMMC(U5001)
Press PWR KeyTP : R11010Come high to low?
Yes
Yes
Yes
Check PM8941Vreg xx level
Check PM8841Vreg xx level
Check PM8941 (U6002)
Check PM8841 (U7000)
Check Power Key, Pin 1 of KBR11000No
Start
Yes
Yes
Yes
Yes
Yes
Yes...

3. TROUBLE SHOOTING
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U5003
U3000
U6002
X6000
U6000
R11010
KBR11000
TOP