Lenovo T420i manual FRU tests, The following table shows the test for each FRU

FRU tests

The following table shows the test for each FRU.

Table 1. FRU tests

FRU	Applicable test
Systemboard	1.	Diagnostics ➙ CPU/Coprocessor
	2.	Diagnostics ➙ Systemboard
	3.	If the docking station or the port replicator is attached to the ThinkPad Notebook,
		detach it.
	4.	Place the computer on a horizontal surface, and run Diagnostics ➙ ThinkPad
		Devices ➙ HDD Active Protection Test.
		Note: Do not apply any physical shock to the computer while the test is running.
Power	Diagnostics ➙ ThinkPad Devices ➙ ac power adapter, Battery 1 (Battery2)
LCD unit	1.	Diagnostics ➙ Video Adapter
	2.	Interactive Tests ➙ Video
Audio	Enter the ThinkPad Setup program and change Serial ATA (SATA) setting to
	Compatibility, and run Diagnostics ➙ Other Device ➙ Conexant Audio.
Speaker	Interactive Tests ➙ Internal Speaker
	Note: Once Audio test is done, the no sound is heard this test. In this case, turn off
	and turn on the computer. Then, run this test again.
Keyboard	1.	Diagnostics ➙ Systemboard ➙ Keyboard
	2.	Interactive Tests ➙ Keyboard
Hard disk drive or solid state	Enter the ThinkPad Setup program and change Serial ATA (SATA) setting to
drive	Compatibility, and run Diagnostics ➙ Fixed Disks.
Diskette drive	1.	Diagnostics ➙ Diskette Drives
	2.	Interactive Tests ➙ Diskette
Optical drive	1.	Diagnostics ➙ Other Devices ➙ Optical Drive
	2.	Interactive Tests ➙ Optical Drive Test
Memory	1.	If two DIMMs are installed, remove one of them and run Diagnostics ➙ System
		Memory.
	2.	If the problem does not recur, return the DIMM to its place, remove the other one,
		and run the test again.
TrackPoint or pointing	If the TrackPoint does not work, check the configuration as specified in the ThinkPad
device	Setup program. If the TrackPoint is disabled, select Automatic to enable it.
	After you use the TrackPoint, the pointer may drift on the screen for a short time. This
	drift can occur when a slight, steady pressure is applied to the TrackPoint pointer.
	This symptom is not a hardware problem. If the pointer stops after a short time, no
	service action is necessary.
	If enabling theTrackPoint does not correct the problem, continue with the following:
	• Interactive Tests ➙ Mouse
Touch Pad	If the Touch Pad does not work, check the configuration as specified in the ThinkPad
	Setup program. If the Touch Pad is disabled, select Automatic to enable it. If enabling
	the Touch Pad does not correct the problem, continue with the following:
	• Interactive Tests ➙ Mouse

Chapter 3. General checkout 33