Personally I'd do the following:
- boot into the bios config menu to make sure it's unlocked (if it's locked and they don't have the password that'd be a dealbreaker for me)
- boot into a live linux environment from usb and test both batteries, keyboard, trackpoint/trackpad, speakers, microphone, wifi, and all external ports (T480 has 2 usb-c, 2 usb-a, ethernet, hdmi, headset, and sd - make sure batteries charge well from both usb-c ports)
- to check the storage health, install nvme-cli if not installed, run
nvme smart-log /dev/nvme0
and check the "percentage_used" value: if it's near 100% it might die and need replacement soon - to check that the vents, airflow, and cooling hardware are in good shape, install stress if not installed, run
stress -c 7
to load up 7 of the 8 available cpu threads, make sure the fan spins up good and strong, and watch /sys/class/thermal/thermal_zone0/temp to make sure the cpu temperature stays under ~90-95 degrees
On my own time later, I'd run memtest86+ overnight from bootable usb to check the memory, then install tlp and run tlp recalibrate
with the laptop on the charger to recalibrate the batteries
Edit: enjoy the new laptop! I hope it works great for you
Sorry, all of the linux stuff is just specific to my own preferences/environment - if you're more familiar with windows it would be best to just use that for testing. Presumably it will come with windows installed?
If so, put some programs on a normal usb storage device and then install/run them from there.
As for the rest:
When you first turn the laptop on, at the red Lenovo splash screen, press Enter repeatedly to get into the boot menu. Once there, it'll give you a list of options with associated keys to access them - go to "BIOS Setup - F10" (or something similar, not sure of the specifics on the X1C 6th gen). If it prompts you for a password to enter that, it's locked.
To test all the ports, plug your usb stick with the apps on it into each of the usb ports and make sure it shows up in explorer; try the same with an sd card if you have one; plug in to a wired ethernet connection and make sure you have internet access through it (disable wifi at the same time to make sure); plug headphones into the jack and make sure they work; plug into an hdmi display if you have one.
To check battery health, run Command Prompt with administrator privileges, then run
powercfg /batteryreport
to generate a battery health reportGood luck!