Usb 故障 - LG KT878 Service Manual

4.14 USB 故障
测试点
电路图
AP_USB_DM
AP_USB_DP
R1006
AP_CLK_POUT
USB_DP
R1348
AP_USB_DP
dDBB_USB_DP
dDBB_USB_DM
AP_VCC_1V8
AP_VUSBIN AP_VCC_1V8
C1002
0.1u
R1002
1k
R1003 12K
TP1001
TP1002
1.5k C1004 100P
C1007 C1008 C1009
1u 0.1u 4.7u
U1302 FSUSB30UMX
1
HSD1+ SEL
0 2
HSD2+ VCC
3
D+ _OE
4
GND HSD1-
5
D- HSD2-
- 125 -
VBAT
C1001 C1003
0.1u 1u
ISP1508AET
U25
C4 C3
TEST CHIP_SEL
B5 A4
VCC_IO1 CLOCK
B2 B1
VCC_IO2 DATA0
C2 A1
RREF DATA1
C1 A2
DM DATA2
D1 A3
DP DATA3
E2 A5
FAULT DATA4
D3 A6
ID DATA5
B3 B6
CFG2 DATA6
B4 C6
CFG1 DATA7
D4 D5
PSW_N NXT
F4 D6
VBUS STP
E3 E5
REG3V3 DIR
F5 E1
XTAL1 CFG0
F6 E6
XTAL2 REF1V8
VBAT
10 R1306
9
8 R1311
7
6
C1308
1u
4.故障解决
AP_VCC_1V8
R1001
10K
AP_ULPI_SEL
AP_ULPI_CLK
AP_ULPI_DATA0
AP_ULPI_DATA1
AP_ULPI_DATA2
AP_ULPI_DATA3
AP_ULPI_DATA4
AP_ULPI_DATA5
AP_ULPI_DATA6
AP_ULPI_DATA7
AP_ULPI_NXT
AP_ULPI_STP
AP_ULPI_DIR
C1005 C1006
0.1u 4.7u
1K
AP_USB_SEL
1K
AP_USB_OE
USB_DM
R1349 0
AP_USB_DM