MiTAC 8355 service manual Keyboard or Touch-Pad Test Error

8355 N/B MAINTENANCE

8.7 Keyboard (K/B) Touch-Pad (T/P) Test Error

Symptom:

Error message of keyboard or touch-pad failure is shown or any key does not work.

Keyboard or Touch-Pad

Test Error

Is K/B or	No
T/P cable connected to		Correct it.
notebook
properly?
Yes

Board-level

Troubleshooting

Check		Yes
U511, J8, J10
for cold Solder?
	No

Re-soldering

Try another known good Keyboard or Touch-pad.

Replace

Motherboard

One of the following parts or signals on the motherboard may be defective, use an oscilloscope to check the signals or replace the parts one at a time and test after each replacement.

Parts		Signals
U509	R640	KBD_CS0	ISA_MCCS#
U511	C759	KI [0:7]	H8_MCCS#

Test Yes Ok?

No

Replace the faulty Keyboard or Touch-Pad

U19	X4	KO [0:15]	H8_T_CLK
J8 ~9	R642	SD [0:7]	T_DATA
SW4~9	C678	ISA_IOR#	SCRL_RIGHT
L517	C679	ISA_IOW#	SCRL_LEFT
R205		ISA_IRQ1	SCRL_UP
R209		ISA_IRQ12	SCRL_DN
L522		ROMCS#	SW_LEFT
L523		H8_KBCS#	SW_RIGHT

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