Usb Trouble Shooting - LG -E977 Service Manual

4.25.USB Trouble shooting

4.25.USB Trouble shooting
The sequence of LGE970 USB is,
USB connected to LGE970  USB_VCHG(C7072) goes to 5V  USB_IO_P go to 3.05V  USB_DATA is triggered
The sequence of LGE977 USB is,
 USB work
USB connected to LGE977 -> USB_VCHG(C7072) goes to 5V -> USB_IO_P go to 3.05V -> USB_DATA is triggered -> USB
Block Diagram of USB & UART connection is shown below
work
Block Diagram of USB & UART connection is shown below
APQ8064 HDMI_DATA
D7
RESET_N
F1
RX2_P MHL_D
G1
RX2_N MHL_DB
G2
RX1_P CBUS_ID
G3
RX1_N
G4
RX0_P
G5
RX0_N
G6
RXC_P
G7
RXC_N VSENSE
U14004
VBUS_EN
D3
RSVDL5 USB_D
B2
RSVDL3 USB_DB
C2
RSVDL4 USB_ID
A1
RSVDL1
D2
RSVDL7 CSCL
C3
RSVDL6 CSDA
B1
RSVDL2
F4
DSCL CI2CA
E1
DSDA
TMODE
F3
RPWR VDDQ
F7
HPD
LGE Internal Use Only
LGE Internal Use Only
SiI9244
USB_ID
APQ_USB_DM
APQ_USB_DP
FL17003
A3
2 4
P2 P4
A4
1 3
P1 P3
A7
CBUS_ID
VCHG
C6
To MUIC
E5
R14021 130K
A5
APQ_USB_DP
A6
APQ_USB_DM
B6
USB_ID
R14029
VREG_S4_1P8
C1
665K
I2C_COMMON_SCL
D1
I2C_COMMON_SDA
R14034 4.7K
VREG_S4_1P8
C7
INT MHL_INT_N
D6
R? : Stuff this pull up resistor if using the alternate I2C address (0x76)
B7
; otherwise leave unstuffed.
A2
C14024
22p
Using PM Internal OVP 28V(USB_IN)
VBUS_USB_IN
QCT's Recommend
TP1
MHL
USB
Switch
From USB Jack
USB_DP
USB_DN
MOTOR_VDP
MOTOR_VDN
2mm
C23020
C23012 22p
USB_DP
ZD23001
USB_DN
1u
- 160 - Copyright © 2013 LG Electronics. Inc. All right reserved.
4. TROUBLE SHOOTING
VCHG
USB_DP
uUSB
USB_DN
Connector
CbUS_ID
GND
D18010
D18014
L18000 82n
L18001 82n
KPD_LED_DRV_N
TP1
Only for training and service purposes
CN1
1 34
2 33
3 32
4 31
5 30
6 29
7 28
8 27
9 26
10 25
11 24
12 23
13 22
14 21
15 20
16 19
17 18