Try this before taking it to the repair shop
[SOLVED] – 😍How to fix Windows 10 PC randomly or unexpectedly shutting down issue?
Is your Windows PC shutting down or restarting without warning? There are several possible causes. For example, it could be a software/hardware conflict, overheating, or a hard drive error. This troubleshooting guide describes multiple solutions to fix automatic shutdown and restart in Windows 10/11.
If your computer keeps crashing, you should boot your computer into Safe Mode or use the System Recovery Options in WinRE to try the solutions below.
If your computer is shutting down automatically, but only at a specific time of day, it is likely due to a scheduled task that you or a third-party program created. To check this:
