LENOVO THINKPAD T14S GEN 4 (02) PDF Document

To ensure general safety while servicing your LENOVO THINKPAD T14S GEN 4, follow these rules:

• Observe good housekeeping in the area of the machines during and after maintenance.

• When lifting any heavy object:

1. Ensure that you can stand safely without slipping.

2. Distribute the weight of the object equally between your feet.

3. Use a slow lifting force. Never move suddenly or twist when you attempt to lift.

4. Lift by standing or by pushing up with your leg muscles; this action removes the strain from the muscles in your back. Do not attempt to lift any object that weighs more than 16 kg (35 lb) or that you think is too heavy for you.

• Do not perform any action that causes hazards to the customer, or that makes the equipment unsafe.

• Before you start the machine, ensure that other service technicians and the customer’s personnel are not in a hazardous position.

• Place removed covers and other parts in a safe place, away from all personnel, while you are servicing the machine.

• Keep your tool case away from walk areas so that other people will not trip over it.

• Do not wear loose clothing that can be trapped in the moving parts of a machine. Ensure that your sleeves are fastened or rolled up above your elbows. If your hair is long, fasten it.

• Insert the ends of your necktie or scarf inside clothing or fasten it with a nonconductive clip, about 8 centimeters (3 inches) from the end.

• Do not wear jewelry, chains, metal-frame eyeglasses, or metal fasteners for your clothing, because metal objects are good electrical conductors.

• Wear safety glasses when you are hammering, drilling, soldering, cutting wire, attaching springs, using solvents, or working in any other conditions that might be hazardous to your eyes.

• After service, reinstall all safety shields, guards, labels, and ground wires. Replace any safety device that is worn or defective.

• Reinstall all covers correctly before returning the machine to the customer.

• Fan louvers on the machine help to prevent overheating of internal components. Do not obstruct fan louvers or cover them with labels or stickers.

Observe the following rules when working on electrical equipment for your LENOVO THINKPAD T14S GEN 4:

• Use only approved tools and test equipment. Some hand tools have handles covered with a soft material that does not insulate you when working with live electrical currents.

• Find the room emergency power-off (EPO) switch, disconnecting switch, or electrical outlet. If an electrical accident occurs, you can then operate the switch or unplug the power cord quickly.

• Do not work alone under hazardous conditions or near equipment that has hazardous voltages.

• Disconnect all power before performing a mechanical inspection, working near power supplies, or removing or installing main units.

• Before you start to work on the machine, unplug the power cord. If you cannot unplug it, ask the customer to power off the wall box that supplies power to the machine, and to lock the wall box in the off position.

• If you need to work on a machine that has exposed electrical circuits, observe the following precautions:

– Ensure that another person, familiar with the power-off controls, is near you.

– Use only one hand when working with powered-on electrical equipment; keep the other hand in your pocket or behind your back to prevent a current from passing through your body.

– When using testers, set the controls correctly and use the approved probe leads and accessories.

– Stand on suitable rubber mats to insulate you from grounds such as metal floor strips and machine frames.

• Regularly inspect and maintain your electrical hand tools for safe operational condition. Do not use worn or broken tools and testers.

• Never assume that power has been disconnected from a circuit. First, check that it has been powered off.

• Always look carefully for possible hazards in your work area, such as moist floors, nongrounded power extension cables, power surges, and missing safety grounds.

• Do not service parts like power supply units and fans with the power on.

• If an electrical accident occurs: use caution, switch off power, and send another person to get medical aid.

To determine whether there are any potentially unsafe conditions on your LENOVO THINKPAD T14S GEN 4, use the following checklist at the beginning of every service task. Begin the checks with the power off, and the power cord disconnected.

Checklist:

1. Check exterior covers for damage (loose, broken, or sharp edges).

2. Turn off the computer. Disconnect the power cord.

3. Check the power cord for:

a. A third-wire ground connector in good condition. Use a meter to measure third-wire ground continuity for 0.1 ohm or less between the external ground pin and the frame ground.

b. The power cord should be the authorized type specified for your computer.

c. Insulation must not be frayed or worn.

4. Check for cracked or bulging batteries.

5. Remove the cover.

6. Check for any obvious non-ThinkPad / non-Lenovo alterations. Use good judgment as to the safety of any such alterations.

7. Check inside the unit for any obvious unsafe conditions, such as metal filings, contamination, water or other liquids, or signs of fire or smoke damage.

8. Check for worn, frayed, or pinched cables.

9. Check that the power-supply cover fasteners (screws or rivets) have not been removed or tampered with.

Any computer part containing transistors or integrated circuits (ICs) should be considered sensitive to electrostatic discharge (ESD). Protect against ESD damage by equalizing the charge so that the machine, the part, the work mat, and the person handling the part are all at the same charge.

When handling ESD-sensitive parts:

• Keep the parts in protective packages until they are inserted into the product.

• Avoid contact with other people.

• Wear a grounded wrist strap against your skin to eliminate static on your body.

• Prevent the part from touching your clothing. Most clothing is insulative and retains a charge even when you are wearing a wrist strap.

• Use a grounded work mat to provide a static-free work surface. The mat is especially useful when handling ESD-sensitive devices.

• Select a grounding system to provide protection that meets the specific service requirement. You can attach an ESD ground clip to any frame ground, ground braid, or green-wire ground.

Use the following strategy to prevent unnecessary expense for replacing and servicing FRUs on your LENOVO THINKPAD T14S GEN 4:

• Ensure that all software fixes, drivers, and UEFI BIOS downloads are installed before replacing any FRUs.

• After a system board is replaced, ensure that the latest UEFI BIOS is loaded to the system board before completing the service action.

• If you are instructed to replace a FRU but the replacement does not correct the problem, reinstall the original FRU before you continue.

• If an adapter or a device consists of more than one FRU, any of the FRUs may be the cause of the error. Before replacing the adapter or device, remove the FRUs, one by one, to see if the symptoms change. Replace only the FRU that changed the symptoms.

Always try to run a low-level format operation before replacing a solid-state drive on your LENOVO THINKPAD T14S GEN 4. This will erase all data on the drive. Ensure that the customer has a current backup of the data before you perform this task.

Attention: The drive startup sequence in the computer you are servicing might have been changed. Be extremely careful during write operations such as copying, saving, or formatting. If you select an incorrect drive, data or programs can be overwritten.

Use the error codes displayed on the screen to diagnose failures. If more than one error code is displayed, begin the diagnosis with the first error code. Whatever causes the first error code might also cause false error codes. If no error code is displayed, see whether the error symptom is listed in the “Symptom-to-FRU index” section of the manual.

Before you go to the checkout guide for your LENOVO THINKPAD T14S GEN 4, be sure to read the following important notes:

• Only certified trained personnel should service the computer.

• Before replacing any FRU, read the entire page on removing and replacing FRUs.

• When you replace FRUs, it is recommended to use new nylon-coated screws.

• Be extremely careful during such write operations as copying, saving, or formatting. Drives in the computer that you are servicing sequence might have been altered. If you select an incorrect drive, data or programs might be overwritten.

• Replace a FRU only with another FRU of the correct model. When you replace a FRU, ensure that the model of the machine and the FRU part number are correct.

• A FRU should not be replaced because of a single, unreproducible failure. Single failures can occur for a variety of reasons that have nothing to do with a hardware defect. Consider replacing a FRU only when a problem recurs. If you suspect that a FRU is defective, clear the error log and run the test again. If the error does not recur, do not replace the FRU.

• Be careful not to replace a nondefective FRU.

To diagnose problems with your LENOVO THINKPAD T14S GEN 4, first identify and verify the failing symptoms in as much detail as possible. Many computer problems can be solved without outside assistance by starting with the troubleshooting information in your computer documentation. The Vantage app is preinstalled on your computer and supports the hardware scan function, combining diagnostic tests, system information, and support.

If you are unable to isolate and repair the problem yourself after running the program, save and print the log files created by the program. You will need these log files when you speak to a technical support representative.

A UEFI diagnostic program is preinstalled on your LENOVO THINKPAD T14S GEN 4. This program enables you to view system information and test some hardware devices such as memory, storage devices, the LCD, and system board buses.

To run the UEFI diagnostic program, do the following:

1. Turn on the computer. If an error code is displayed, refer to the “Symptom-to-FRU index” for troubleshooting hints.

2. When the logo screen is displayed, repeatedly press and release the F10 key. The main screen of the UEFI diagnostic program is displayed.

3. Follow the instructions on the screen to use the program.

The following table displays the main items of the UEFI diagnostic program:

To verify if a battery or an AC power adapter is functional on your LENOVO THINKPAD T14S GEN 4, do the following:

1. Turn off the computer.

2. Connect the AC power adapter.

3. Turn on the computer. If the computer can be turned on, it means that either the battery or the AC power adapter is functional.

4. Insert a straightened paper clip into the emergency-reset hole to reset the computer. If the computer is still powered on, it means that the AC power adapter is functional.

5. Turn off the computer.

6. Disconnect the AC power adapter and turn on the computer. If the computer can be turned on, it means that the battery is functional.

If your LENOVO THINKPAD T14S GEN 4 fails only when the AC power adapter is used:

• If the system status indicator does not blink three times when an AC power source is connected, check the power cord of the AC power adapter for correct continuity and installation.

• If the computer does not charge during operation, proceed to check the built-in battery and operational charging.

To check the AC power adapter information:

1. Connect the computer to a power outlet and turn on the computer.

2. Start the Vantage app, and then click Hardware Settings ➙ Power. The AC power adapter information is displayed.

Ensure that you use the AC power adapter that is shipped with the computer to provide enough power. Otherwise, a message will be displayed, prompting you that the computer will not be charged or will be charged slowly.

Your LENOVO THINKPAD T14S GEN 4 supports only batteries specially designed for this system. If an unauthorized battery is installed, the system will not charge.

To check whether the battery charges properly during operation, do the following:

1. Discharge the battery to 50% or lower.

2. Connect the computer to AC power to charge the battery. If the battery status icon in the Windows notification area indicates that the battery is not charging, remove the battery and let it return to room temperature.

3. Reinstall the battery. If the battery is still not charging, replace the battery.

4. Check the battery status icon again. If the same error still exists, replace the system board.

To check the coin-cell battery on your LENOVO THINKPAD T14S GEN 4, do the following:

1. Power off the computer, and unplug the AC power adapter from it.

2. Turn the computer upside down.

3. Remove the built-in battery.

4. Remove the coin-cell battery.

5. Measure the voltage of the battery. The voltage should be between +2.5 to +3.2 V dc for the red wire, with the black wire as ground.

• If the voltage is correct, replace the system board.

• If the voltage is not correct, replace the coin-cell battery.

• If the coin-cell battery discharges quickly after replacement, replace the system board.

To reset or restore Windows on your LENOVO THINKPAD T14S GEN 4, you can use Lenovo recovery options or Window recovery options.

• Use Lenovo recovery options: Go to the Lenovo support website section for creating recovery media and follow the on-screen instructions.

• Use Window recovery options: Go to the PC support website, detect your computer or manually select your computer model, then click Diagnostics ➙ Operating system Diagnostics and follow the on-screen instructions.

To remove the power-on password on your LENOVO THINKPAD T14S GEN 4, do one of the following:

If no supervisor password has been set:

1. Turn off the computer.

2. Remove the battery.

3. Remove the coin-cell battery.

4. Turn on the computer and wait until the POST ends. The password prompt will not be displayed.

5. Reinstall the coin-cell battery and the battery.

If a supervisor password has been set and is known:

1. Turn on the computer.

2. When the ThinkPad logo is displayed, immediately press F1.

3. Type the supervisor password to enter the UEFI BIOS menu.

4. Select Security.

5. Select Password.

6. Select Power-On Password.

7. Type the current supervisor password in the Enter Current Password field. Then, leave the Enter New Password field blank, and press Enter twice.

8. In the “Changes have been saved” window, press Enter.

9. Press F10 to save changes and exit.

To remove a system management password on your LENOVO THINKPAD T14S GEN 4, do the following:

If no supervisor password has been set:

1. Turn off the computer and disconnect AC power.

2. Disable the built-in battery.

3. Remove the base cover assembly.

4. Remove the built-in battery.

5. Remove the coin-cell battery.

6. Reinstall the coin-cell battery.

7. Reinstall the built-in battery.

8. Reinstall the base cover assembly.

9. Reconnect AC power.

10. Turn on the computer and wait until the POST ends. The password prompt will not appear.

If a supervisor password has been set and is known:

1. Turn on the computer.

2. When the ThinkPad logo is displayed, immediately press F1.

3. Type the supervisor password to enter the ThinkPad Setup program.

4. Select Security.

5. Select Password.

6. Select System Management Password.

7. Type the current supervisor password in the Enter Current Password field. Then leave the Enter New Password field blank, and press Enter twice.

8. In the “Changes have been saved” window, press Enter.

9. Press F10 to save changes and exit the ThinkPad Setup program.

To reduce power consumption, your LENOVO THINKPAD T14S GEN 4 has two power management modes: sleep and hibernation.

Sleep mode: The screen goes blank and all internal devices are still powered on with lower power consumption. To enter sleep mode, press Fn+4 or open the Start menu. The computer also enters sleep mode automatically after a period of inactivity or when the battery power is low. To resume, press the power button.

Hibernation mode: The system status, RAM, VRAM, and setup data are stored on the solid-state drive, and the system is powered off. The computer enters hibernation mode by closing the lid, pressing the power button (if configured), or after a period of inactivity. When the power is turned on, the computer returns from hibernation and resumes operation.

Lenovo SmartBeep technology enables you to decode beep errors with your smartphone when a black screen occurs with beeps from your computer. To decode the beep error, download the proper diagnostic app and install it on your smartphone. Run the app and place the smartphone near the computer. Press the Fn key on your computer to emit the beep again. The app will decode the beep error and show possible solutions.

Here are some common beep error codes and their solutions:

First, run the LCD Self Test to determine if the LCD functions normally. To run the test:

1. Ensure the computer is connected to AC power. Then, press the power button for about seven seconds to turn off the computer.

2. Press Fn, left Ctrl, and the power button at the same time. If the computer displays five solid colors in sequence, the LCD functions normally.

3. The test lasts about 20 seconds and then exits automatically. You can also press the power button to exit the test.

Use the following table to troubleshoot specific symptoms:

The bottom view of your LENOVO THINKPAD T14S GEN 4 features an Emergency-reset hole. You can insert a straightened paper clip into this hole to reset the computer if it becomes unresponsive.

Your LENOVO THINKPAD T14S GEN 4 contains the following types of CRUs and FRUs:

• Self-service CRUs: Refer to parts that can be replaced easily by customers themselves or by trained service technicians at an additional cost.

• Optional-service CRUs: Refer to parts that can be replaced by customers with a greater skill level. Trained service technicians can also provide service to replace the parts under the type of warranty designated for the customer’s machine.

• FRUs: Refer to parts that must be replaced only by trained service technicians. If customers choose to replace the FRUs by themselves, the product warranty might be affected.

Ensure that the following service tool kit is prepared before you service a LENOVO THINKPAD T14S GEN 4:

Note: The silicone grease can be applied to the surfaces of the microprocessor and heatsink to eliminate air gaps.

Loose screws can cause a reliability problem. Your computer uses special nylon-coated screws to maintain tight connections. When servicing your LENOVO THINKPAD T14S GEN 4, tighten screws as follows:

• Plastic to plastic: Turn an additional angle of 90 degrees after the screw head touches the surface of the plastic part.

• Logic card to plastic: Turn an additional angle of 180 degrees after the screw head touches the surface of the logic card.

Ensure that you use the correct screw and it is recommended to use new screws for replacements. If you have a torque screwdriver, tighten all screws firmly to the torque specified for each step.

Before servicing the computer, carefully read the following instructions. Before replacing any FRU, ensure that you disable Fast Startup first and then disable the built-in battery.

To disable Fast Startup:

1. Go to Control Panel and view by Large icons or Small icons.

2. Click Power Options, and then click “Choose what the power buttons do” on the left pane.

3. Click “Change settings that are currently unavailable” at the top.

4. If prompted by User Account Control (UAC), click Yes.

5. Clear the “Turn on fast startup” check box, and then click Save changes.

To disable the built-in battery:

1. Restart your computer. When the logo screen is displayed, immediately press F1 to enter the UEFI BIOS menu.

2. Select Config ➙ Power. The Power submenu is displayed.

3. Select “Disable built-in battery” and press Enter.

4. Select Yes in the Setup Confirmation window. The built-in battery is disabled and the computer turns off automatically. Wait three to five minutes to let the computer cool.

If the computer you are servicing has a nano-SIM card installed, remove the card with the tray together. The tray is located on the rear of the laptop. Use a SIM eject tool or a small paperclip to press the button inside the small hole on the tray to eject it.

To remove the base cover assembly on your LENOVO THINKPAD T14S GEN 4, first loosen the captive screws securing the cover, then pry up the cover to release the latches and remove it.

When applying labels to the new base cover assembly:

• The new base cover assembly FRU is shipped with a kit containing labels of several kinds. Apply those labels when you replace the base cover assembly.

• For labels that are not shipped with the new base cover assembly, peel them from the old base cover assembly, and adhere them to the new one.

For access, first remove the “1010 Base cover assembly”.

Attention: The M.2 solid-state drive is sensitive. Inappropriate handling might cause damage and permanent loss of data. Observe these guidelines:

• Replace the M.2 solid-state drive only for repair.

• Before replacing, make a backup copy of all data.

• Do not apply pressure to the drive.

• Do not touch the contact edge or circuit board.

• Do not subject the drive to physical shocks or vibration.

Removal steps of the M.2 2280 solid-state drive and its bracket (if any):

1. Remove the single screw securing the M.2 solid-state drive bracket.

2. Remove the bracket.

3. Pull the M.2 solid-state drive out of its slot.

If the thermal pad is damaged during replacement, remove the old one and apply a new one on the system board.

Screw Information:

• Step 1: M2 × 3.5 mm, flat-head, nylon-coated (1), Black, Torque: 0.181 Nm (1.85 kgf-cm)

For access, first remove the “1010 Base cover assembly”.

Removal steps of the wireless WAN card and its bracket (if any):

1. Disconnect the antenna cables from the Wireless WAN card.

2. Remove the screw securing the Wireless WAN card bracket.

3. Remove the bracket.

4. Pull the Wireless WAN card out of its slot.

When installing: Ensure that you connect the cables with different colors to the corresponding connectors on the card: the orange cable to ORANGE, the blue cable to BLUE, the white and grey cable to WHITE GREY, and the black and grey cable to BLACK GREY.

If the thermal pad is damaged, replace it with a new one on the system board.

Screw Information:

• Step 2: M2 × 2.3 mm, flat-head, nylon-coated (1), Black, Torque: 0.181 Nm (1.85 kgf-cm)

For access, first remove the “1010 Base cover assembly”.

Important Notice: A built-in battery FRU should not be replaced unless a diagnostic test from the Vantage app shows that the battery is defective, or if the battery is physically damaged.

Removal steps of the built-in battery:

1. Disconnect the battery connector from the system board.

2. Remove the three screws securing the battery.

3. Lift and remove the battery.

When installing:

• Ensure that the connector is attached firmly.

• Ensure that the base cover assembly is secured in place. Otherwise, the battery connection may fail.

Screw Information:

• Step 2: M1.98 × 3 mm, flat-head, nylon-coated (3), Silver, Torque: 0.181 Nm (1.85 kgf-cm)