Lenovo ThinkPad T14 Gen 3 Randomly Shuts Down

• Overheating
• Software is outdated
• The battery is not fully functional
• The power adapter is incorrect

• Check Lenovo's website to verify battery integrity: (https://support.lenovo.com/us/en/solutio...)
• Then you should verify the power status indicator. The power status indicator illuminates whenever the computer is on and not in standby or hibernation mode. This can help determine if the battery is even turning on.

• It could initially be that the power outlet is faulty, so plug in a device or light to verify that it actually does work.
• It could also be as simple as a power connection or outlet. Check all power connections and remove any power strips and surge protectors to connect the AC adapter directly to the AC power outlet, to ensure that the connection is there and works.
• Inspect the AC adapter; Check for any physical damage to the adapter, cables, and plugs, and ensure the power cable is firmly attached to the adapter brick and the system, and remove from any docks or power bars.
• Verify that the AC power adapter is correct for the system (check the user manual, which can be found online if needed)

• If the battery has recently been replaced, try a hard reset (shut down the computer, remove the power, wait 30 seconds or so, attach the power, and then power the system back on).

• Try reloading the BIOS default settings, be sure to save.
• Install all applicable updates offered on the support site. Once done, turn off the computer.
• While in the off state, press the emergency reset hole located at the bottom panel, see page 5 user guide.
• This should power on the machine and let it boot to the OS.
• Turn off the computer again, then this time try turning it on through the computer's power button.

• Check for overheating. Ensure that the laptop's vents are not blocked or covered and are free from dust and debris. You can also use compressed air to clean the ducts as well.

• Make sure the software is up to date. Use the Lenovo Vantage app to check for and install any available updates for your system's software and drivers. This app also provides diagnostic tools that can help identify any issues.
• Run Hardware Diagnostics. You can run hardware diagnostics to check for any underlying hardware issues the device may have. Instructions for running diagnostics can be found on the Lenovo Support Website (https://support.lenovo.com/uy/en/)
• If trouble persists, contact support at Lenovo.

resources

https://forums.lenovo.com/t5/ThinkPad-T4... 

Lenovo ThinkPad T14 Gen 3 Randomly Shuts Down