Laptop restarts only if power cable is plugged on

[Lukas Gerulis]

Hello and thanks to everyone who regards for my problem.

Problem:

My new laptop restarts on any stressful activity (like playing games, or 3D Mark test) if have my power supply cable on. If I do these activities from the battery, everything works perfectly fine.
CPU and GPU temperature, just before the crash, won't get high. CPU stays around 40-70, GPU around 40-50.

Link for the video example of the problem:
Youtube link

Question: Do you have any idea of what could cause this problem? And is it possible to fix it? How much would it cost?

Story behind:

Yesterday I got my hands on this second hand laptop, from a guy who was selling it on the internet. I met him in the mall, who shown me if laptop works properly. We played witcher 3, he ran 3D Mark test, because I asked if he can download it before we meet. Everything was working properly, I handed the money and left. But when I tried to test it at home, with the power supply cable on, computer was shutting down every time I was doing anything stressful (playing Witcher, running 3D mark test). As long as I was using it without cable, everything were working properly, jut like in the mall. Now this guy won't answer his phone, or reply on my emails, so it looks like a scam....

Laptop Spec:
Clevo P650rs-g
i7 6700hq CPU
16GB (2x8) RAM 2300mhz
GTX 1070 8GB
256gb SSD
1TB HDD. Windows 10 Home (looks freshly installed)
Charger is original (checked).

 

[rgd1101]

MERGED QUESTION
Question from Lukas Gerulis : "Laptop restarts only if power cable is plugged on"

Hello and thanks to everyone who regards for my problem.

Problem:

My new laptop restarts on any stressful activity (like playing games, or 3D Mark test) if have my power supply cable on. If I do these activities from the battery, everything works perfectly fine.
CPU and GPU temperature, just before the crash, won't get high. CPU stays around 40-70, GPU around 40-50.

Link for the video example of the problem:
youtube link

Question: Do you have any idea of what could cause this problem? And is it possible to fix it? How much would it cost?

Story behind:

Yesterday I got my hands on this second hand laptop, from a guy who was selling it on the internet. I met him in the mall, who shown me if laptop works properly. We played witcher 3, he ran 3D Mark test, because I asked if he can download it before we meet. Everything was working properly, I handed the money and left. But when I tried to test it at home, with the power supply cable on, computer was shutting down every time I was doing anything stressful (playing Witcher, running 3D mark test). As long as I was using it without cable, everything were working properly, jut like in the mall. Now this guy won't answer his phone, or reply on my emails, so it looks like a scam....