MiTAC 8355 service manual USB Test Error, PartsSignals

8355 N/B MAINTENANCE

8.10 USB Test Error

Symptom:

An error occurs when a USB I/O device is installed.

USB Test Error

Check if the USB device is installed properly. (Including charge board.)

Test		Yes
			Correct it
OK?
	No

Replace another known good USB device.

Re-test		Yes
			Correct it
OK?
	No

Board-level

Troubleshooting

Replace

Motherboard

Check the following parts for cold solder or one of the following parts on the MB and Charge BD 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:Signals:

U20	L28	C45	+5VS
U3	L14	R510	USB_OC[0:3]#
U501	L38	R509	USBP0_P
J521-524	R360-363	C504	USBP0_N
R8	R356-359		USBP1_P
R10-12	C502		USBP1_N
C48	C868		USBP2_P
C50	C506		USBP2_N
L501	C508		USBP3_P
L503	R3		USBP3_N
L504	R544
L1	C33
L25	C1

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