Things with Ubuntu were working absolutely fine, but suddenly, the laptop started overheating whenever I logged into Ubuntu. And that lead to automatic shutdown. I realised that it was definitely due to heat. This overheat crossed a limit and it started affecting even when I logged into Windows. With appropriate service, the laptop fan was cleaned and things are absolutely back to normal in Windows 8. But, there are still problems with using Ubuntu.
After a while, it closes automatically. And, if the laptop is on battery, it doesn't switch on immediately, unless you connect to power. I tried without battery and the problem is still the same. So , battery problems are ruled out.
My laptop is HP- pavilion, g6-2313ax notebook. I would like to stress again, it was working really fine, but one fine day, this problem started to occur. When searchd over net, they said something about the kernel version and it being updated could be a reason.
I tried the one suggested in this link as well, but it did not work! link.
I got a small intuition as to the birth of this problem. I reinstalled Windows 8 once with ubuntu on it and thus it removed the grub. To retrieve it, I followed few online steps! link. Ever since the I got the grub back, I have been facing this issue. But I cleared my whole hard disk and properly installed Ubuntu and Windows again. Still, the problem exists.
What can I do to solve this?