laptop shut-down randomly

[maaln1]

Hi.
I bought a Lenovo flex 2-14 inch core i3 4010U about a year ago. For about 3 weeks my laptop just shut down randomly; sometimes after 10 hours working and sometimes after 15 minutes. The hardware was scanned by the application of Lenovo and no problem was found. I took the laptop to a computer repair company and they told me the rtc circuit had problem so they replaced it and also replaced the RAM but it didn’t work. They told me it might be caused by the battery so that was replaced too; but still my laptop shuts down randomly. Does anybody happen to know the reason?

 

[Cazauxx]

When it shut downs does it go completely off or does it say "Shutting down"

 

[maaln1]

When it shut downs does it go completely off or does it say "Shutting down"

it completely goes off!

 

[velo3100]

It sounds like either the charger or the power jack is faulty.