Lenovo ThinkPad T490 Hardware Maintenance Manual

Table 5. LCD-related symptoms
Symptom or error
FRU or action, in sequence
No beep, power-on indicator on, and a blank LCD during
POST.
1. Run LCD Self Test.
2. Replace the system board.
• LCD backlight not working.
• LCD too dark.
• LCD brightness cannot be adjusted.
• LCD contrast cannot be adjusted.
1. Reseat the LCD connectors.
2. Replace the LCD assembly.
3. Replace the system board.
• LCD screen unreadable.
• Characters missing pixels.
• Screen abnormal.
• Wrong color displayed.
1. See important note for “LCD-related symptoms.”
2. Reseat all LCD connectors.
3. Replace the LCD assembly.
4. Replace the system board.
Horizontal or vertical lines displayed on LCD. Replace the LCD assembly.
Intermittent problems
Intermittent system hang problems can be due to a variety of causes that have nothing to do with a hardware
defect, such as cosmic radiation, ESD, or software errors. FRU replacement should be considered only when
a problem recurs.
When analyzing an intermittent problem, do the following:
1. Run the diagnostic test for the system board in loop mode at least 10 times.
2. If no error is detected, do not replace any FRUs.
3. If any error is detected, replace the FRU shown by the FRU code. Rerun the test to verify that no more
errors exist.
Undetermined problems
If the diagnostic tests did not identify the device that has failed, if wrong devices are installed, or if the
system simply is not operating, follow these procedures to isolate the failing FRU (do not isolate FRUs that
have no defects).
Verify that all attached devices are supported by the computer.
Verify that the power supply being used at the time of the failure is operating correctly. (See “Power system
checkout” on page 28)
1. Turn off the computer.
2. Visually check each FRU for damage. Replace any damaged FRU.
3. Remove or disconnect all of the following devices:
a. Non-ThinkPad devices
b. Devices attached to the dock
c. Printer, mouse, and other external devices
d. Battery
e. Hard disk drive or solid-state drive
f. External diskette drive or optical drive
g. Memory module
4. Turn on the computer.
5. Determine whether the problem has been solved.
6. If the problem does not recur, reconnect the removed devices one at a time until you find the failing FRU.
7. If the problem remains, replace the following FRUs one at a time (do not replace a nondefective FRU):
a. System board
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T490 and P43s Hardware Maintenance Manual

Lenovo ThinkPad T490 Specifications

General

Form factor	Clamshell
Product type	Ultrabook
Product color	Black
Market positioning	Business
LED backlight	Yes
Display diagonal	14 \
Bus type	OPI
Tjunction	100 °C
Processor cache	6 MB
Processor cores	4
Processor model	i5-8265U
System bus rate	4 GT/s
Processor family	Intel® Core™ i5
Processor socket	BGA 1528
Processor threads	8
Processor codename	Whiskey Lake
Configurable TDP-up	25 W
Processor frequency	1.6 GHz
Processor cache type	Smart Cache
Configurable TDP-down	10 W
Processor lithography	14 nm
Processor manufacturer	Intel
PCI Express slots version	3.0
Processor boost frequency	3.9 GHz
Processor operating modes	64-bit
PCI Express configurations	1x4, 2x2
Thermal Design Power (TDP)	15 W
Configurable TDP-up frequency	1.8 GHz
Configurable TDP-down frequency	0.8 GHz
Maximum number of PCI Express lanes	16
Internal memory	8 GB
Memory clock speed	2400 MHz
Internal memory type	DDR4-SDRAM
Maximum internal memory	- GB
SSD capacity	The Solid State Drive's storage capacity in Gigabytes.
SSD interface	SATA III
Storage media	SSD
Total storage capacity	256 GB
Compatible memory cards	MicroSD (TransFlash)
Number of SSDs installed	1
On-board graphics card ID	0x3EA0
Discrete graphics card model	Not available
On-board graphics card family	Intel® UHD Graphics
Maximum on-board graphics card memory	32 GB
On-board graphics card OpenGL version	4.5
On-board graphics card base frequency	300 MHz
On-board graphics card DirectX version	12.0
On-board graphics card dynamic frequency (max)	1100 MHz
Number of built-in speakers	2
Antenna type	-
Wi-Fi standards	802.11a, Wi-Fi 5 (802.11ac), 802.11b, 802.11g, Wi-Fi 4 (802.11n)
Top Wi-Fi standard	Wi-Fi 5 (802.11ac)
Ethernet LAN data rates	100, 1000 Mbit/s
USB 2.0 ports quantity	USB 2.0 ports have a data transmission speed of 480 Mbps, and are backwards compatible with USB 1.1 ports. You can connect all kinds of peripheral devices to them.
Keyboard layout	QWERTY
Pointing device	Touchpad
Number of battery cells	3
AC adapter power	65 W
Processor ARK ID	149088
Processor package size	46x24 mm
Supported instruction sets	AVX 2.0, SSE4.1, SSE4.2
Intel Identity Protection Technology version	1.00
Intel Stable Image Platform Program (SIPP) version	0.00

Weight and Dimensions

Depth	227 mm
Width	329 mm
Height	17.9 mm
Weight	1460 g