My Sony vaio turns off after a few seconds... Help?

[Kannashi]

So I left my My sony Vaio back home while i went on vacation, and when I came back and tried to turn it on, it turns off after a few seconds. I've tried going to the BIOS and setting the values to default and see if it helps, but it doesn't, and sometimes turns off when i'm in it. It tried doing a repair, but same thing- it powered off. Sometimes it manages to get to the login screen, but it will then turn off not soon after.

What I've tried:
- Going into the BIOS
- Removing the battery for a while and putting it back.
- removing both battery and charger, and pressing the power button to do a "Hard reset"
- removing the RAM module
- replacing the HDD with a known working HDD

Not sure what else to do.

Specs:

Model: Sony Vaio SVS 151 A11L
CPU: i7
RAM: 8gb
HDD: 750GB
O/S: Windows 10
O/D: Some blu ray reader

 

[hang-the-9]

Did you try turning it on with just the wall power, no battery? If playing around with the power does not help, could be a dead motherboard.

 

[Craig876]

SOLVED: I had the same problem with a Sony vaio VGN-TZ170N. I found that the thermal paste between the CPU and its heat sink was hard and brittle, not soft. Also it had been squeezed out from between the CPU and heat sink. I replaced the paste, and it started booting again immediately. I think that the CPU used to turn itself off because it overheated in only 2 seconds.