MiTAC 7521 PLUS/N - Manual (Page 125)

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7521 7521 Plus / N N/B MAINTENANCE Plus / N N/B MAINTENANCE
8.9 USB PORT TEST ERROR
An error occurs when a USB I/O device is installed.
USB TEST ERROR
1. Check if the USB device is
installed properly.
2. Confirm USB driver is installed
ok.
Test
OK?
Re-test
OK?
Change M/B or go
into board-level
Troubleshooting.
YES
NO
Correct It.
YES
NO
Change the
faulty part
then end.
Board-level
Troubleshooting for
USB test error
Check the following parts for cold solder or one of the following
parts on the mother-board may be defective, use an oscilloscope
to check the following signal or replace the parts one at a time and
test after each replacement.
Parts:
U24, RP21, CP7
F502, R20, R19
C506, L2, C14
F503, R22, R23
C507, L6, C25
R141, R140, R142
R143, , L12
L8, L504, L511
Signals:
USBP1- USB_B1
USBP1+ USB_B2
USBP0-
USB_B3
USBP0+ USB_B4
D/USBP1- USB_A1
D/USBP1+ USB_A2
D/USBP0- USB_A3
D/USBP0+ USB_A4
USB_OC0#
USB_OC1#
Try another known
good USB device.