Couple of weeks ago I was playing and during the game laptop just turned off, without any signs of lag or any sounds. Just off as electricity was off and no battery inside (but it was inside). Then I was not able to turn it on, so I unplugged and plugged in the battery connector and after this it turned on. Same thing repeated after 20-30 minutes. Then I tried to work in it by removing battery. Same thing with shut down happened after 10-20 minutes of just showing me Desktop. I made all possible diagnostics of hardware and some showed me issues with battery. I purchased new one, today I tried to turn it on with new battery and same shut down happened when Windows was just loading. After this I can’t turn it on again. I don’t know what can it be, but definitely not a battery as I understand. What else I can do to find a problem? I am planning to visit repair shop, but I don’t wanna pay for diagnostics, I am a poor student.

Thanks in advance.