How to find out, which hardware component causes a power failure on a Windows 7 machine (Kernel Power error 41(63))?

Since February 2016 my notebook occasionally (up to several times a day) stops working (all of a sudden the screen tus white or black), or reboots itself.

According to eventvwr, there are unexpected power interruptions, which cause this.

How can I systematically (no guesses) find out,

1. whether the error is caused by software or hardware (according to the article above, this error may be caused by software problem), and
2. if it's a hardware problem, which component is causing it (which component I have to replace to fix the error)

?

My first guess was the AC-DC adapter, which had an old cable. I replaced it by a new one, but the error persists.