Hi,
Does it shutdown while you're using it or was it while it's on idle? Here are some troubleshooting steps that may help.
- First is to do a hard reboot, remove the battery and unplug the AC adapter then press and hold the power button for 20 seconds then try booting it up again.
- Next to test would be to remove the battery again and plug in just the AC adapter and observe if it will shutdown or not.
- If the same problem will persist do also try a different AC adapter that has the same voltage and observe if it will still shutdown by itself.
- Do also try opening the laptop and clean the inside of it and remove the dust off the fans and apply new thermal paste.
If the laptop shutdown while it's on idle do try changing some settings in Power Option.
- Open Power Options then click on Change Plan Settings then Change Advanced Power Settings.
- Expand Hard Disk then set Turn off Hard disk after to NEVER.
- Expand Sleep and set Allow hyrbid sleep to OFF.
- Set Hibernate after to NEVER.
- Do also set Sleep Mode to Never.
- Click Apply and OK then test it again and see if the same problem will persist or not.